* [RFC PATCH v1 0/2] perf sysinfo: Add subcommand to probe and summarize PMU capabilities
@ 2026-10-16 21:32 Ian Rogers
2026-10-16 21:32 ` [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing Ian Rogers
2026-10-16 21:32 ` [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test Ian Rogers
0 siblings, 2 replies; 5+ messages in thread
From: Ian Rogers @ 2026-10-16 21:32 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark
Cc: linux-perf-users, linux-kernel, Stephane Eranian
Determining what performance monitoring hardware, driver capabilities,
and event/metric support are available on a system currently requires
piecing together sysfs files under /sys/bus/event_source/devices/,
perf list output, and trial-and-error perf_event_open() calls. Across
architectures and SoCs, support varies widely: an advanced system
provides core PMUs with zero-skid precise event sampling (PEBS/IBS/SPE),
hardware branch stack recording (LBR/BRBE), user-space counter reading
(rdpmc), memory profiling (DATA_SRC), hardware AUX trace PMUs, memory
and PCIe/IO interconnect bandwidth PMUs, and multi-level pipeline metric
drill-down hierarchies, whereas a minimal system may only offer software
timer sampling.
This RFC series introduces 'perf sysinfo' to inspect, actively probe,
and summarize the PMU and performance monitoring capabilities of a live
system or a recorded perf.data file:
- Patch 1 adds PMU environment reconstruction from perf_env headers
(perf_pmus__read_from_env()), public duplicate-collapsing PMU scan
helpers, and active live capability probing via perf_event_open()
(perf_pmu__probe()). Probing tests counting, sampling, branch stack
sampling, precise_ip levels (:p, :pp, :ppp) and empirically measured
branch instruction skid across an 8,192-nop runway, supported
perf_event_sample_format bits, user/intr general-purpose and SIMD
register masks, memory profiling events, privilege exclusion
modifiers, execution features (leader sampling, sw_grouping,
auto-counter reload, AUX pause/resume/sample), user-space rdpmc
availability/enablement and PMC bit-width, and maximum event group
sizes (both openable and simultaneously active without multiplexing).
- Patch 2 adds the 'perf sysinfo' subcommand, documentation, and shell
test. By default, 'perf sysinfo' outputs a colorized system capability
summary, pipeline metric drill-down hierarchy (via <metric>_group
chains), overall system rating (Advanced, Standard, Basic, Minimal),
and any missing baseline features. Passing '-p'/'--pmus' (or a PMU
glob filter, '-v'/'--verbose', '-a'/'--all', or '-j'/'--json')
displays detailed per-PMU static and probed attributes.
Example default output on an Intel AlderLake hybrid system:
$ perf sysinfo
Summary:
Core PMUs (2, hybrid): cpu_atom, cpu_core
Core features:
Interrupt-based sampling: supported
Precise event sampling: supported (max_precise: 3 [3 - SAMPLE_IP must have 0 skid, or uses randomization])
Branch stack sampling (LBR/BRBE): supported (depth: 32 branches)
User-space counter reading (rdpmc): supported
Leader sampling: supported
Memory profiling events (DATA_SRC): supported
Hardware AUX trace PMUs: intel_bts, intel_pt
Bus & uncore monitoring:
Memory bandwidth PMUs: uncore_imc, uncore_imc_free_running
PCIe / IO interconnect bandwidth PMUs: uncore_arb
Events & metrics:
Available events: 3161 total (76 sysfs, 3085 json) across 28 PMUs
Available metrics: 438 metrics in 192 groups (advanced)
Metric drill-down levels (6): L1 (TopdownL1: 7 metrics), L2 (TopdownL2: 14 metrics), L3 (TopdownL3: 44 metrics), L4 (TopdownL4: 45 metrics), L5 (TopdownL5: 15 metrics), L6 (TopdownL6: 9 metrics)
System rating: Advanced (core PMU with precise sampling, branch stack (LBR), user rdpmc, bus PMUs, and metric drill-down)
Example filtered per-PMU output:
$ perf sysinfo cpu_core
cpu_core (type: 4 [PERF_TYPE_RAW], core):
CPUs: 0-15 (16 CPUs)
Capabilities: branches=32, max_precise=3, pmu_name=alderlake_hybrid
Formats: event (config:0-7), pc (config:19), edge (config:18), offcore_rsp (config1:0-63), ldlat (config1:0-15), inv (config:23), umask (config:8-15), frontend (config1:0-23), cmask (config:24-31)
Events: 1563 total (20 sysfs, 1543 json)
Memory events: ldlat-loads ({cpu_core/mem-loads-aux/,cpu_core/mem-loads,ldlat=30/}:P), ldlat-stores (cpu_core/mem-stores/P)
Probed capabilities (event: cpu_core/cycles/):
Modes: counting, sampling, branch_stack
Precise sampling: :p (1 - SAMPLE_IP must have constant skid), :pp (2 - SAMPLE_IP requested to have 0 skid), :ppp (3 - SAMPLE_IP must have 0 skid, or uses randomization) (max_precise: 3)
Measured branch skid (instructions from branch):
level 0 (no :p): min 105, max 174, avg 156.8 (0/32 exact_ip)
level 1 (:p) : min 1, max 1, avg 1.0 (0/31 exact_ip)
level 2 (:pp) : min 0, max 0, avg 0.0 (31/31 exact_ip)
level 3 (:ppp) : min 0, max 0, avg 0.0 (32/32 exact_ip)
Sample types: ip, tid, time, addr, read, callchain, id, cpu, period, stream_id, raw, branch_stack, regs_user, stack_user, weight, data_src, identifier, transaction, regs_intr, aux, cgroup, data_page_size, code_page_size, weight_struct
User registers: AX, BX, CX, DX, SI, DI, BP, SP, IP, FLAGS, CS, SS, R8, R9, R10, R11, R12, R13, R14, R15
Intr registers: AX, BX, CX, DX, SI, DI, BP, SP, IP, FLAGS, CS, SS, R8, R9, R10, R11, R12, R13, R14, R15, XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6, XMM7, XMM8, XMM9, XMM10, XMM11, XMM12, XMM13, XMM14, XMM15
Memory events (probed): ldlat-loads, ldlat-stores (sample types: addr, weight, data_src, transaction, data_page_size, weight_struct)
Exclusion modifiers: exclude_user, exclude_kernel, exclude_hv, exclude_idle, exclude_host, exclude_guest
Features: leader_sampling, sw_grouping, inherit, sample_freq, write_backward, callchain, data_src, weight, pinned, exclusive, format_lost, user_rdpmc, user_time, user_time_zero
User space counter reading (rdpmc): available, enabled, working (width: 48 bits)
Max event group size: 18 (active: 8)
Max GP event group size: 16 (active: 7)
This patch series was generated with the assistance of antigravity and
Gemini 4.0.
Ian Rogers (2):
perf pmus: Add PMU environment loading and live capability probing
perf sysinfo: Add sysinfo subcommand, documentation, and test
tools/perf/Build | 1 +
tools/perf/Documentation/perf-sysinfo.txt | 109 ++
tools/perf/Documentation/perf.txt | 2 +-
tools/perf/builtin-help.c | 3 +-
tools/perf/builtin-sysinfo.c | 1958 ++++++++++++++++++++
tools/perf/builtin.h | 1 +
tools/perf/perf.c | 1 +
tools/perf/tests/shell/sysinfo.sh | 71 +
tools/perf/util/mem-events.c | 14 +-
tools/perf/util/mem-events.h | 3 +
tools/perf/util/pmu.c | 1976 ++++++++++++++++++++-
tools/perf/util/pmu.h | 135 +-
tools/perf/util/pmus.c | 221 ++-
tools/perf/util/pmus.h | 4 +
14 files changed, 4486 insertions(+), 13 deletions(-)
create mode 100644 tools/perf/Documentation/perf-sysinfo.txt
create mode 100644 tools/perf/builtin-sysinfo.c
create mode 100755 tools/perf/tests/shell/sysinfo.sh
--
2.56.0.212.g129ede20d9-goog
^ permalink raw reply [flat|nested] 5+ messages in thread
* [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing
2026-10-16 21:32 [RFC PATCH v1 0/2] perf sysinfo: Add subcommand to probe and summarize PMU capabilities Ian Rogers
@ 2026-10-16 21:32 ` Ian Rogers
2026-10-16 21:56 ` sashiko-bot
2026-10-16 21:32 ` [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test Ian Rogers
1 sibling, 1 reply; 5+ messages in thread
From: Ian Rogers @ 2026-10-16 21:32 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark
Cc: linux-perf-users, linux-kernel, Stephane Eranian
Add helpers to reconstruct PMU lists and capabilities from perf_env
headers (for perf.data files), expose duplicate uncore PMU scanning and
mem-events formatting helpers, and add perf_pmu__probe() to actively
probe live PMU capabilities via perf_event_open().
Probed capabilities stored in struct perf_pmu::probed include counting,
sampling, and branch_stack modes, precise_ip levels and measured branch
instruction skid, supported perf_event_sample_format flags, user and
interrupt sampling registers, memory profiling events and sample types,
privilege exclusion modifiers, leader sampling, software event grouping,
auto-counter reload, AUX actions (start_paused, pause, resume,
aux_sample), user-space counter reading (rdpmc) and PMC width, and
rotating event group size limits.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/util/mem-events.c | 14 +-
tools/perf/util/mem-events.h | 3 +
tools/perf/util/pmu.c | 1976 +++++++++++++++++++++++++++++++++-
tools/perf/util/pmu.h | 135 ++-
tools/perf/util/pmus.c | 221 +++-
tools/perf/util/pmus.h | 4 +
6 files changed, 2342 insertions(+), 11 deletions(-)
diff --git a/tools/perf/util/mem-events.c b/tools/perf/util/mem-events.c
index 0cdcb47647bd..eb2a4973e385 100644
--- a/tools/perf/util/mem-events.c
+++ b/tools/perf/util/mem-events.c
@@ -79,12 +79,12 @@ int perf_pmu__mem_events_num_mem_pmus(struct perf_pmu *pmu)
return num;
}
-static const char *perf_pmu__mem_events_name(struct perf_pmu *pmu, int i,
- char *buf, size_t buf_size)
+const char *perf_pmu__mem_events_name(struct perf_pmu *pmu, int i,
+ char *buf, size_t buf_size)
{
struct perf_mem_event *e;
- if (i >= PERF_MEM_EVENTS__MAX || !pmu)
+ if (i >= PERF_MEM_EVENTS__MAX || !pmu || !pmu->mem_events)
return NULL;
e = &pmu->mem_events[i];
@@ -193,13 +193,13 @@ static bool perf_pmu__mem_events_supported(const char *mnt, struct perf_pmu *pmu
return !stat(path, &st);
}
-static int __perf_pmu__mem_events_init(struct perf_pmu *pmu)
+int perf_pmu__mem_events_init_pmu(struct perf_pmu *pmu)
{
const char *mnt = sysfs__mount();
bool found = false;
int j;
- if (!mnt)
+ if (!mnt || !pmu || !pmu->mem_events)
return -ENOENT;
for (j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
@@ -209,7 +209,7 @@ static int __perf_pmu__mem_events_init(struct perf_pmu *pmu)
* If the event entry isn't valid, skip initialization
* and "e->supported" will keep false.
*/
- if (!e->tag)
+ if (!e || !e->tag)
continue;
e->supported |= perf_pmu__mem_events_supported(mnt, pmu, e);
@@ -225,7 +225,7 @@ int perf_pmu__mem_events_init(void)
struct perf_pmu *pmu = NULL;
while ((pmu = perf_pmus__scan_mem(pmu)) != NULL) {
- if (__perf_pmu__mem_events_init(pmu))
+ if (perf_pmu__mem_events_init_pmu(pmu))
return -ENOENT;
}
diff --git a/tools/perf/util/mem-events.h b/tools/perf/util/mem-events.h
index 38b14c03392c..64517ca053d3 100644
--- a/tools/perf/util/mem-events.h
+++ b/tools/perf/util/mem-events.h
@@ -31,7 +31,10 @@ extern struct perf_mem_event perf_mem_events[PERF_MEM_EVENTS__MAX];
extern bool perf_mem_record[PERF_MEM_EVENTS__MAX];
int perf_pmu__mem_events_parse(struct perf_pmu *pmu, const char *str);
+int perf_pmu__mem_events_init_pmu(struct perf_pmu *pmu);
int perf_pmu__mem_events_init(void);
+const char *perf_pmu__mem_events_name(struct perf_pmu *pmu, int i,
+ char *buf, size_t buf_size);
struct perf_mem_event *perf_pmu__mem_events_ptr(struct perf_pmu *pmu, int i);
struct perf_pmu *perf_mem_events_find_pmu(void);
diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
index 01753d5c69d1..0d1c5ba7d426 100644
--- a/tools/perf/util/pmu.c
+++ b/tools/perf/util/pmu.c
@@ -38,7 +38,22 @@
#include "strbuf.h"
#include "fncache.h"
#include "util/evsel_config.h"
+#include "cloexec.h"
+#include "dwarf-regs.h"
+#include "evlist.h"
+#include "mem-events.h"
+#include "mmap.h"
+#include "perf_regs.h"
+#include "rlimit.h"
+#include "util/sample.h"
+#include "../perf-sys.h"
+#include <linux/hw_breakpoint.h>
+#include <sys/ioctl.h>
+#include <sys/mman.h>
+#include <sched.h>
#include <regex.h>
+#include <elf.h>
+#include <link.h>
#define UNIT_MAX_LEN 31 /* max length for event unit name */
@@ -2139,7 +2154,7 @@ size_t perf_pmu__num_events(struct perf_pmu *pmu)
size_t nr;
if (perf_pmu__is_tracepoint(pmu))
- return tp_pmu__num_events(pmu);
+ return pmu->sysfs_aliases_loaded ? 0 : tp_pmu__num_events(pmu);
if (perf_pmu__is_hwmon(pmu))
return hwmon_pmu__num_events(pmu);
if (perf_pmu__is_drm(pmu))
@@ -2275,7 +2290,7 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bool skip_duplicate_pmus,
size_t size_rem;
if (perf_pmu__is_tracepoint(pmu))
- return tp_pmu__for_each_event(pmu, state, cb);
+ return pmu->sysfs_aliases_loaded ? 0 : tp_pmu__for_each_event(pmu, state, cb);
if (perf_pmu__is_hwmon(pmu))
return hwmon_pmu__for_each_event(pmu, state, cb);
if (perf_pmu__is_drm(pmu))
@@ -2564,6 +2579,37 @@ static int perf_pmu__new_caps(struct list_head *list, char *name, char *value)
return -ENOMEM;
}
+int perf_pmu__add_cap(struct perf_pmu *pmu, const char *name, const char *value)
+{
+ struct perf_pmu_caps *caps;
+
+ if (!pmu || !name || !value)
+ return -EINVAL;
+ if (perf_pmu__get_cap(pmu, name))
+ return 0;
+
+ caps = zalloc(sizeof(*caps));
+ if (!caps)
+ return -ENOMEM;
+
+ caps->name = strdup(name);
+ if (!caps->name) {
+ free(caps);
+ return -ENOMEM;
+ }
+ caps->value = strdup(value);
+ if (!caps->value) {
+ zfree(&caps->name);
+ free(caps);
+ return -ENOMEM;
+ }
+ list_add_tail(&caps->list, &pmu->caps);
+ pmu->nr_caps++;
+ if (!strcmp(name, "max_precise"))
+ pmu->max_precise = atoi(value);
+ return 0;
+}
+
static void perf_pmu__del_caps(struct perf_pmu *pmu)
{
struct perf_pmu_caps *caps, *tmp;
@@ -2798,9 +2844,1935 @@ void perf_pmu__delete(struct perf_pmu *pmu)
zfree(&pmu->name);
zfree(&pmu->alias_name);
zfree(&pmu->id);
+ zfree(&pmu->probed.probe_event);
free(pmu);
}
+#define MAX_PROBE_GROUP_SIZE 64
+#define MAX_PROBE_CANDIDATES 16
+
+static unsigned long dummy_bp_var;
+
+static bool get_self_uprobe_target(char *exe_path, __u64 *out_offset)
+{
+ ElfW(Ehdr) ehdr;
+ int fd;
+ bool found = false;
+
+ if (!realpath("/proc/self/exe", exe_path))
+ return false;
+
+ fd = open(exe_path, O_RDONLY | O_CLOEXEC);
+ if (fd < 0)
+ return false;
+
+ if (pread(fd, &ehdr, sizeof(ehdr), 0) != sizeof(ehdr) ||
+ memcmp(ehdr.e_ident, ELFMAG, SELFMAG) != 0 ||
+ ehdr.e_phentsize < sizeof(ElfW(Phdr))) {
+ close(fd);
+ return false;
+ }
+
+ for (unsigned int i = 0; i < ehdr.e_phnum; i++) {
+ ElfW(Phdr) phdr;
+ off_t pos = (off_t)ehdr.e_phoff + (off_t)i * ehdr.e_phentsize;
+
+ if (pread(fd, &phdr, sizeof(phdr), pos) != sizeof(phdr))
+ break;
+ if (phdr.p_type != PT_LOAD || !(phdr.p_flags & PF_X))
+ continue;
+ if (ehdr.e_entry >= phdr.p_vaddr &&
+ ehdr.e_entry < phdr.p_vaddr + phdr.p_filesz) {
+ *out_offset = phdr.p_offset + (ehdr.e_entry - phdr.p_vaddr);
+ found = true;
+ break;
+ }
+ }
+
+ close(fd);
+ return found;
+}
+
+struct probe_candidates {
+ char *names[MAX_PROBE_CANDIDATES];
+ size_t nr;
+};
+
+static void probe_candidates__add(struct probe_candidates *cands, const char *str)
+{
+ if (cands->nr >= MAX_PROBE_CANDIDATES || !str)
+ return;
+ for (size_t i = 0; i < cands->nr; i++) {
+ if (!strcmp(cands->names[i], str))
+ return;
+ }
+ cands->names[cands->nr] = strdup(str);
+ if (cands->names[cands->nr])
+ cands->nr++;
+}
+
+static void probe_candidates__exit(struct probe_candidates *cands)
+{
+ for (size_t i = 0; i < cands->nr; i++)
+ zfree(&cands->names[i]);
+ cands->nr = 0;
+}
+
+static int collect_probe_candidate_cb(void *vstate, struct pmu_event_info *info)
+{
+ struct probe_candidates *cands = vstate;
+ char buf[512];
+
+ if (info->deprecated)
+ return 0;
+ if (info->str && strstr(info->str, "=?"))
+ return 0;
+ if (!info->name)
+ return 0;
+
+ if (info->pmu && info->pmu->type == PERF_TYPE_TRACEPOINT) {
+ probe_candidates__add(cands, info->name);
+ return 1;
+ } else if (strchr(info->name, '/')) {
+ probe_candidates__add(cands, info->name);
+ } else if (info->pmu && info->pmu->name) {
+ snprintf(buf, sizeof(buf), "%s/%s/", info->pmu->name, info->name);
+ probe_candidates__add(cands, buf);
+ } else {
+ probe_candidates__add(cands, info->name);
+ }
+
+ return cands->nr >= MAX_PROBE_CANDIDATES ? 1 : 0;
+}
+
+static bool parse_candidate_attr(const char *event_str, struct perf_event_attr *attr)
+{
+ struct evlist *evlist;
+ struct parse_events_error err;
+ struct evsel *evsel;
+ int ret;
+
+ evlist = evlist__new();
+ if (!evlist)
+ return false;
+
+ parse_events_error__init(&err);
+ ret = __parse_events(evlist, event_str, /*pmu_filter=*/NULL,
+ /*cputype_filter=*/false, &err, /*fake_pmu=*/false,
+ /*warn_if_reordered=*/false, /*fake_tp=*/false);
+ parse_events_error__exit(&err);
+ if (ret || evlist__empty(evlist)) {
+ evlist__put(evlist);
+ return false;
+ }
+
+ evsel = evlist__first(evlist);
+ *attr = evsel->core.attr;
+ evlist__put(evlist);
+ return true;
+}
+
+static int select_probe_cpu(const struct perf_pmu *pmu)
+{
+ struct perf_cpu_map *online = perf_cpu_map__new_online_cpus();
+ int cpu = 0;
+
+ if (pmu->cpus && !perf_cpu_map__is_empty(pmu->cpus)) {
+ int nr = perf_cpu_map__nr(pmu->cpus);
+
+ cpu = perf_cpu_map__cpu(pmu->cpus, 0).cpu;
+ if (online) {
+ for (int i = 0; i < nr; i++) {
+ struct perf_cpu c = perf_cpu_map__cpu(pmu->cpus, i);
+
+ if (perf_cpu_map__has(online, c)) {
+ cpu = c.cpu;
+ break;
+ }
+ }
+ }
+ } else if (online && !perf_cpu_map__is_empty(online)) {
+ cpu = perf_cpu_map__cpu(online, 0).cpu;
+ }
+
+ perf_cpu_map__put(online);
+ return cpu >= 0 ? cpu : 0;
+}
+
+static bool try_open_attr_variants(struct perf_event_attr *attr,
+ bool is_uncore, int pmu_cpu,
+ unsigned long flags,
+ pid_t *out_pid, int *out_cpu,
+ int *last_err)
+{
+ pid_t pids[2];
+ size_t nr_pids = 2;
+
+ if (is_uncore) {
+ pids[0] = -1;
+ pids[1] = 0;
+ } else {
+ pids[0] = 0;
+ pids[1] = -1;
+ }
+
+ for (size_t p = 0; p < nr_pids; p++) {
+ pid_t pid = pids[p];
+
+ for (int samp = 0; samp < 2; samp++) {
+ for (int priv = 0; priv < 4; priv++) {
+ struct perf_event_attr try_attr = *attr;
+ int fd;
+
+ try_attr.size = sizeof(try_attr);
+ try_attr.disabled = 1;
+ try_attr.read_format = 0;
+ if (samp == 0) {
+ try_attr.sample_period = 0;
+ try_attr.freq = 0;
+ try_attr.sample_type = 0;
+ } else {
+ try_attr.sample_period = 10000;
+ try_attr.freq = 0;
+ try_attr.sample_type = PERF_SAMPLE_IP;
+ }
+
+ if (priv >= 1)
+ try_attr.exclude_kernel = 1;
+ if (priv >= 2)
+ try_attr.exclude_hv = 1;
+ if (priv >= 3)
+ try_attr.exclude_guest = 1;
+
+ fd = sys_perf_event_open(&try_attr, pid, pmu_cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ *attr = try_attr;
+ *out_pid = pid;
+ *out_cpu = pmu_cpu;
+ return true;
+ }
+ if (*last_err == 0 || *last_err == ENOENT || *last_err == EINVAL)
+ *last_err = errno;
+ }
+ }
+ }
+ return false;
+}
+
+static bool check_group_active(int leader_fd, int last_fd)
+{
+ u64 before[3] = { 0, 0, 0 };
+ u64 after[3] = { 0, 0, 0 };
+ u64 f_before[3] = { 0, 0, 0 };
+ u64 f_after[3] = { 0, 0, 0 };
+ u64 delta_ena, delta_run;
+ bool check_follower = false;
+
+ if (read(leader_fd, before, sizeof(before)) != sizeof(before))
+ return false;
+
+ if (last_fd >= 0 && read(last_fd, f_before, sizeof(f_before)) == sizeof(f_before))
+ check_follower = true;
+
+ if (ioctl(leader_fd, PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) < 0)
+ return false;
+
+ for (int spin = 0; spin < 20000; spin++)
+ barrier();
+
+ ioctl(leader_fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP);
+
+ if (read(leader_fd, after, sizeof(after)) != sizeof(after))
+ return false;
+
+ if (check_follower && read(last_fd, f_after, sizeof(f_after)) != sizeof(f_after))
+ return false;
+
+ delta_ena = after[1] - before[1];
+ delta_run = after[2] - before[2];
+ if (delta_ena == 0 || delta_run != delta_ena)
+ return false;
+
+ if (check_follower) {
+ u64 f_delta_ena = f_after[1] - f_before[1];
+ u64 f_delta_run = f_after[2] - f_before[2];
+
+ if (f_delta_ena == 0 || f_delta_run != f_delta_ena)
+ return false;
+ }
+
+ return true;
+}
+
+static void probe_group_limits(const struct perf_event_attr *attrs, size_t nr_attrs,
+ pid_t pid, int cpu, unsigned long flags,
+ int *max_open, bool *open_capped,
+ int *max_active, bool *active_capped)
+{
+ struct perf_event_attr leader_attr;
+ int leader_fd;
+ int fds[MAX_PROBE_GROUP_SIZE];
+ int nr_followers = 0;
+ bool has_time_read = true;
+ bool active_ok = true;
+ enum rlimit_action set_rlimit = NO_CHANGE;
+ cpu_set_t saved_affinity, probe_affinity;
+ bool affinity_changed = false;
+
+ *max_open = 0;
+ *open_capped = false;
+ *max_active = 0;
+ *active_capped = false;
+
+ if (!attrs || nr_attrs == 0)
+ return;
+
+ if (pid == 0 && cpu >= 0) {
+ CPU_ZERO(&saved_affinity);
+ if (sched_getaffinity(0, sizeof(saved_affinity), &saved_affinity) == 0) {
+ CPU_ZERO(&probe_affinity);
+ CPU_SET(cpu, &probe_affinity);
+ if (sched_setaffinity(0, sizeof(probe_affinity), &probe_affinity) == 0)
+ affinity_changed = true;
+ }
+ }
+
+ leader_attr = attrs[0];
+ leader_attr.disabled = 1;
+ leader_attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING;
+
+ leader_fd = sys_perf_event_open(&leader_attr, pid, cpu, -1, flags);
+ if (leader_fd < 0) {
+ leader_attr.read_format = 0;
+ has_time_read = false;
+ leader_fd = sys_perf_event_open(&leader_attr, pid, cpu, -1, flags);
+ }
+ if (leader_fd < 0)
+ goto out_affinity;
+
+ *max_open = 1;
+ if (has_time_read && check_group_active(leader_fd, -1))
+ *max_active = 1;
+ else
+ active_ok = false;
+
+ for (int count = 2; count <= MAX_PROBE_GROUP_SIZE; count++) {
+ struct perf_event_attr follower_attr = attrs[(count - 1) % nr_attrs];
+ int fd;
+
+ follower_attr.disabled = 0;
+ follower_attr.read_format = leader_attr.read_format;
+
+ fd = sys_perf_event_open(&follower_attr, pid, cpu, leader_fd, flags);
+ if (fd < 0 && errno == EMFILE && rlimit__increase_nofile(&set_rlimit))
+ fd = sys_perf_event_open(&follower_attr, pid, cpu, leader_fd, flags);
+ if (fd < 0 && follower_attr.read_format != 0) {
+ follower_attr.read_format = 0;
+ fd = sys_perf_event_open(&follower_attr, pid, cpu, leader_fd, flags);
+ }
+ if (fd < 0)
+ break;
+
+ fds[nr_followers++] = fd;
+ *max_open = count;
+ if (active_ok && has_time_read) {
+ if (check_group_active(leader_fd, fd))
+ *max_active = count;
+ else
+ active_ok = false;
+ }
+ }
+
+ if (*max_open >= MAX_PROBE_GROUP_SIZE)
+ *open_capped = true;
+ if (*max_active >= MAX_PROBE_GROUP_SIZE)
+ *active_capped = true;
+
+ for (int i = 0; i < nr_followers; i++)
+ close(fds[i]);
+ close(leader_fd);
+
+out_affinity:
+ if (affinity_changed)
+ sched_setaffinity(0, sizeof(saved_affinity), &saved_affinity);
+}
+
+enum probe_exclude_flag {
+ PROBE_EXCLUDE_USER,
+ PROBE_EXCLUDE_KERNEL,
+ PROBE_EXCLUDE_HV,
+ PROBE_EXCLUDE_IDLE,
+ PROBE_EXCLUDE_HOST,
+ PROBE_EXCLUDE_GUEST,
+};
+
+static bool test_exclude_flag(const struct perf_event_attr *base_attr,
+ pid_t pid, int cpu, unsigned long flags,
+ enum probe_exclude_flag which)
+{
+ struct perf_event_attr attr = *base_attr;
+ int fd;
+
+ switch (which) {
+ case PROBE_EXCLUDE_USER:
+ attr.exclude_user = 1;
+ break;
+ case PROBE_EXCLUDE_KERNEL:
+ attr.exclude_kernel = 1;
+ attr.exclude_user = 0;
+ break;
+ case PROBE_EXCLUDE_HV:
+ attr.exclude_hv = 1;
+ break;
+ case PROBE_EXCLUDE_IDLE:
+ attr.exclude_idle = 1;
+ break;
+ case PROBE_EXCLUDE_HOST:
+ attr.exclude_host = 1;
+ attr.exclude_guest = 0;
+ break;
+ case PROBE_EXCLUDE_GUEST:
+ attr.exclude_guest = 1;
+ attr.exclude_host = 0;
+ break;
+ default:
+ return false;
+ }
+
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ return true;
+ }
+ if (which == PROBE_EXCLUDE_USER && attr.exclude_kernel == 1) {
+ attr.exclude_kernel = 0;
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ return true;
+ }
+ }
+ return false;
+}
+
+static void probe_sample_types(struct perf_pmu *pmu,
+ const struct perf_event_attr *base_attr,
+ pid_t pid, int cpu, unsigned long flags)
+{
+ u64 reg_bit = BIT_ULL(perf_arch_reg_ip(EM_HOST)) ?: 1ULL;
+ u64 bulk_mask = PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_TIME |
+ PERF_SAMPLE_ADDR | PERF_SAMPLE_READ | PERF_SAMPLE_CALLCHAIN |
+ PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD |
+ PERF_SAMPLE_STREAM_ID | PERF_SAMPLE_RAW | PERF_SAMPLE_REGS_USER |
+ PERF_SAMPLE_STACK_USER | PERF_SAMPLE_WEIGHT | PERF_SAMPLE_DATA_SRC |
+ PERF_SAMPLE_IDENTIFIER | PERF_SAMPLE_TRANSACTION |
+ PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_AUX | PERF_SAMPLE_CGROUP |
+ PERF_SAMPLE_DATA_PAGE_SIZE | PERF_SAMPLE_CODE_PAGE_SIZE |
+ PERF_SAMPLE_WEIGHT_STRUCT;
+ struct perf_event_attr b_attr = *base_attr;
+ int b_fd;
+
+ b_attr.disabled = 1;
+ b_attr.sample_period = base_attr->sample_period ?: 10000;
+ b_attr.sample_type = bulk_mask;
+ b_attr.sample_regs_user = reg_bit;
+ b_attr.sample_regs_intr = reg_bit;
+ b_attr.sample_stack_user = 64;
+ b_attr.inherit = 0;
+ b_fd = sys_perf_event_open(&b_attr, pid, cpu, -1, flags);
+ if (b_fd >= 0) {
+ close(b_fd);
+ pmu->probed.sample_types |= bulk_mask;
+ }
+
+ for (unsigned int shift = 0; (1ULL << shift) < PERF_SAMPLE_MAX; shift++) {
+ u64 bit = 1ULL << shift;
+ struct perf_event_attr attr = *base_attr;
+ int fd;
+
+ if (pmu->probed.sample_types & bit)
+ continue;
+
+ attr.disabled = 1;
+ attr.sample_period = base_attr->sample_period ?: 10000;
+ attr.sample_type = bit;
+
+ switch (bit) {
+ case PERF_SAMPLE_BRANCH_STACK:
+ attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY |
+ (attr.exclude_kernel ? PERF_SAMPLE_BRANCH_USER : 0);
+ break;
+ case PERF_SAMPLE_REGS_USER:
+ attr.sample_regs_user = reg_bit;
+ break;
+ case PERF_SAMPLE_REGS_INTR:
+ attr.sample_regs_intr = reg_bit;
+ break;
+ case PERF_SAMPLE_STACK_USER:
+ attr.sample_stack_user = 64;
+ break;
+ case PERF_SAMPLE_READ:
+ attr.inherit = 0;
+ break;
+ default:
+ break;
+ }
+
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ if (fd < 0 && bit == PERF_SAMPLE_BRANCH_STACK) {
+ attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY;
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ }
+ if (fd < 0 && bit != PERF_SAMPLE_IP) {
+ attr.sample_type = PERF_SAMPLE_IP | bit;
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ }
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.sample_types |= bit;
+ }
+ }
+
+ pmu->probed.can_branch_stack = !!(pmu->probed.sample_types & PERF_SAMPLE_BRANCH_STACK);
+ pmu->probed.can_callchain = !!(pmu->probed.sample_types & PERF_SAMPLE_CALLCHAIN);
+ pmu->probed.can_data_src = !!(pmu->probed.sample_types & PERF_SAMPLE_DATA_SRC);
+ pmu->probed.can_weight = !!(pmu->probed.sample_types & PERF_SAMPLE_WEIGHT);
+}
+
+static void probe_pmu_regs_one(const struct perf_pmu *pmu,
+ const struct perf_event_attr *base_attr,
+ pid_t pid, int cpu, unsigned long flags,
+ int max_precise, bool intr,
+ u64 *out_mask, int *out_abi,
+ u64 *out_simd_mask, u64 *out_pred_mask)
+{
+ int dummy_abi = -1;
+ u64 gpr_mask = intr ? perf_intr_reg_mask(EM_HOST, &dummy_abi) :
+ perf_user_reg_mask(EM_HOST, &dummy_abi);
+ u64 sample_type = intr ? PERF_SAMPLE_REGS_INTR : PERF_SAMPLE_REGS_USER;
+ u64 mask = 0;
+ int abi = 0;
+ struct perf_event_attr attr = *base_attr;
+ int fd;
+
+ attr.disabled = 1;
+ attr.sample_period = base_attr->sample_period ?: 10000;
+ attr.sample_type = sample_type;
+
+ if (gpr_mask) {
+ if (intr)
+ attr.sample_regs_intr = gpr_mask;
+ else
+ attr.sample_regs_user = gpr_mask;
+
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ mask |= gpr_mask;
+ } else {
+ for (int b = 0; b < 64; b++) {
+ if (!(gpr_mask & BIT_ULL(b)))
+ continue;
+ if (intr)
+ attr.sample_regs_intr = BIT_ULL(b);
+ else
+ attr.sample_regs_user = BIT_ULL(b);
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ mask |= BIT_ULL(b);
+ }
+ }
+ }
+ }
+
+ if (perf_pmu__is_software(pmu)) {
+ *out_mask = mask;
+ *out_abi = abi;
+ return;
+ }
+
+ /*
+ * Probe extended registers outside the base GPR mask. On x86, check
+ * APX EGPRs (R16-R31, bits 24..39) and SSP (bit 40) with
+ * sample_simd_regs_enabled=1 if the host supports SIMD ABI; otherwise
+ * check legacy PEBS XMM registers (bits 32..63) which require
+ * precise_ip > 0 on interrupt register sampling.
+ */
+ if (EM_HOST == EM_X86_64 || EM_HOST == EM_386) {
+ int host_abi = 0;
+ u64 host_mask = intr ? perf_intr_reg_mask(EM_HOST, &host_abi) :
+ perf_user_reg_mask(EM_HOST, &host_abi);
+
+ if ((host_abi & PERF_SAMPLE_REGS_ABI_SIMD) && (host_mask & ~gpr_mask)) {
+ u64 egpr_masks[] = { GENMASK_ULL(39, 24), BIT_ULL(40) };
+
+ for (size_t i = 0; i < ARRAY_SIZE(egpr_masks); i++) {
+ struct perf_event_attr e_attr = *base_attr;
+
+ e_attr.size = sizeof(e_attr);
+ e_attr.disabled = 1;
+ e_attr.sample_period = base_attr->sample_period ?: 10000;
+ e_attr.sample_type = sample_type;
+ e_attr.sample_simd_regs_enabled = 1;
+ if (intr)
+ e_attr.sample_regs_intr = egpr_masks[i];
+ else
+ e_attr.sample_regs_user = egpr_masks[i];
+
+ fd = sys_perf_event_open(&e_attr, pid, cpu, -1, flags);
+ if (fd < 0 && intr && max_precise > 0) {
+ e_attr.precise_ip = 1;
+ fd = sys_perf_event_open(&e_attr, pid, cpu, -1, flags);
+ }
+ if (fd >= 0) {
+ close(fd);
+ mask |= egpr_masks[i];
+ abi |= PERF_SAMPLE_REGS_ABI_SIMD;
+ }
+ }
+ }
+ }
+
+ if (!(abi & PERF_SAMPLE_REGS_ABI_SIMD)) {
+ u64 ext_mask = GENMASK_ULL(63, 32) & ~gpr_mask;
+ struct perf_event_attr x_attr = *base_attr;
+ bool batch_ok = false;
+
+ x_attr.disabled = 1;
+ x_attr.sample_period = base_attr->sample_period ?: 10000;
+ x_attr.sample_type = sample_type;
+ if (intr && max_precise > 0)
+ x_attr.precise_ip = 1;
+
+ if (ext_mask) {
+ if (intr)
+ x_attr.sample_regs_intr = ext_mask;
+ else
+ x_attr.sample_regs_user = ext_mask;
+
+ fd = sys_perf_event_open(&x_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ mask |= ext_mask;
+ batch_ok = true;
+ }
+ }
+
+ if (!batch_ok) {
+ for (int b = 0; b < 64; b++) {
+ const char *rname;
+
+ if (gpr_mask & BIT_ULL(b))
+ continue;
+ rname = perf_reg_name(b, EM_HOST, EF_HOST, 0);
+ if (!rname || !strcmp(rname, "unknown"))
+ continue;
+ if (intr)
+ x_attr.sample_regs_intr = BIT_ULL(b);
+ else
+ x_attr.sample_regs_user = BIT_ULL(b);
+ fd = sys_perf_event_open(&x_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ mask |= BIT_ULL(b);
+ }
+ }
+ }
+ }
+
+ for (int is_pred = 0; is_pred <= 1; is_pred++) {
+ bool pred = is_pred != 0;
+ u64 class_mask = intr ?
+ perf_intr_simd_reg_class_mask(EM_HOST, pred) :
+ perf_user_simd_reg_class_mask(EM_HOST, pred);
+ u64 supported_classes = 0;
+
+ for (int reg_c = 0; reg_c < 64; reg_c++) {
+ struct perf_event_attr s_attr = *base_attr;
+ u16 qwords = 0;
+ u64 bitmap;
+
+ if (!(class_mask & BIT_ULL(reg_c)))
+ continue;
+ bitmap = intr ?
+ perf_intr_simd_reg_class_bitmap_qwords(EM_HOST, reg_c,
+ &qwords, pred) :
+ perf_user_simd_reg_class_bitmap_qwords(EM_HOST, reg_c,
+ &qwords, pred);
+ if (!bitmap || !qwords)
+ continue;
+
+ s_attr.size = sizeof(s_attr);
+ s_attr.disabled = 1;
+ s_attr.sample_period = base_attr->sample_period ?: 10000;
+ s_attr.sample_type = sample_type;
+ s_attr.sample_simd_regs_enabled = 1;
+ if (pred) {
+ s_attr.sample_simd_pred_reg_qwords = qwords;
+ if (intr)
+ s_attr.sample_simd_pred_reg_intr = bitmap;
+ else
+ s_attr.sample_simd_pred_reg_user = bitmap;
+ } else {
+ s_attr.sample_simd_vec_reg_qwords = qwords;
+ if (intr)
+ s_attr.sample_simd_vec_reg_intr = bitmap;
+ else
+ s_attr.sample_simd_vec_reg_user = bitmap;
+ }
+
+ fd = sys_perf_event_open(&s_attr, pid, cpu, -1, flags);
+ if (fd < 0 && intr && max_precise > 0) {
+ s_attr.precise_ip = 1;
+ fd = sys_perf_event_open(&s_attr, pid, cpu, -1, flags);
+ }
+ if (fd >= 0) {
+ close(fd);
+ supported_classes |= BIT_ULL(reg_c);
+ }
+ }
+
+ if (pred)
+ *out_pred_mask = supported_classes;
+ else
+ *out_simd_mask = supported_classes;
+ }
+
+ *out_mask = mask;
+ *out_abi = abi;
+}
+
+static bool try_open_mem_evlist(struct evlist *evlist,
+ const struct perf_event_attr *base_attr,
+ pid_t pid, int cpu, unsigned long flags,
+ int precise_ip, u64 sample_type)
+{
+ int fds[16];
+ size_t nr_fds = 0;
+ int leader_fd = -1;
+ struct evsel *evsel;
+ bool ok = true;
+
+ evlist__for_each_entry(evlist, evsel) {
+ struct perf_event_attr attr = evsel->core.attr;
+ int fd;
+
+ if (nr_fds >= ARRAY_SIZE(fds)) {
+ ok = false;
+ break;
+ }
+
+ attr.disabled = (leader_fd < 0) ? 1 : 0;
+ attr.sample_period = attr.sample_period ?: 10000;
+ attr.sample_type = sample_type;
+ attr.exclude_user = base_attr->exclude_user;
+ attr.exclude_kernel = base_attr->exclude_kernel;
+ attr.exclude_hv = base_attr->exclude_hv;
+ attr.exclude_idle = base_attr->exclude_idle;
+ attr.exclude_host = base_attr->exclude_host;
+ attr.exclude_guest = base_attr->exclude_guest;
+ if (evsel->precise_max || precise_ip > 0)
+ attr.precise_ip = precise_ip;
+
+ fd = sys_perf_event_open(&attr, pid, cpu, leader_fd, flags);
+ if (fd < 0) {
+ ok = false;
+ break;
+ }
+ if (leader_fd < 0)
+ leader_fd = fd;
+ fds[nr_fds++] = fd;
+ }
+
+ for (size_t i = nr_fds; i > 0; i--)
+ close(fds[i - 1]);
+
+ return ok && nr_fds > 0;
+}
+
+static void probe_mem_events(struct perf_pmu *pmu,
+ const struct perf_event_attr *base_attr,
+ pid_t pid, int cpu, unsigned long flags)
+{
+ static const u64 extra_mem_stypes[] = {
+ PERF_SAMPLE_WEIGHT,
+ PERF_SAMPLE_WEIGHT_STRUCT,
+ PERF_SAMPLE_PHYS_ADDR,
+ PERF_SAMPLE_DATA_PAGE_SIZE,
+ PERF_SAMPLE_TRANSACTION,
+ };
+
+ if (!pmu->mem_events)
+ return;
+
+ perf_pmu__mem_events_init_pmu(pmu);
+
+ for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
+ struct perf_mem_event *e = perf_pmu__mem_events_ptr(pmu, j);
+ const char *s;
+ char buf[256];
+ struct evlist *evlist;
+ struct parse_events_error err;
+ struct evsel *first;
+ int max_p, min_p, working_p = -1;
+ u64 base_stype = PERF_SAMPLE_IP | PERF_SAMPLE_ADDR | PERF_SAMPLE_DATA_SRC;
+ int ret;
+
+ if (!e || !e->tag || !e->supported)
+ continue;
+
+ s = perf_pmu__mem_events_name(pmu, j, buf, sizeof(buf));
+ if (!s)
+ continue;
+
+ evlist = evlist__new();
+ if (!evlist)
+ continue;
+
+ parse_events_error__init(&err);
+ ret = __parse_events(evlist, s, /*pmu_filter=*/NULL,
+ /*cputype_filter=*/false, &err, /*fake_pmu=*/false,
+ /*warn_if_reordered=*/false, /*fake_tp=*/false);
+ parse_events_error__exit(&err);
+ if (ret || evlist__empty(evlist)) {
+ evlist__put(evlist);
+ continue;
+ }
+
+ first = evlist__first(evlist);
+ if (first->precise_max) {
+ max_p = pmu->probed.max_precise > 0 ? pmu->probed.max_precise : 3;
+ min_p = 1;
+ } else {
+ max_p = first->core.attr.precise_ip;
+ min_p = first->core.attr.precise_ip;
+ }
+
+ for (int p = max_p; p >= min_p; p--) {
+ if (try_open_mem_evlist(evlist, base_attr, pid, cpu,
+ flags, p, base_stype)) {
+ working_p = p;
+ break;
+ }
+ }
+
+ if (working_p >= 0) {
+ pmu->probed.mem_events_mask |= (1u << j);
+ pmu->probed.mem_sample_types |= PERF_SAMPLE_ADDR | PERF_SAMPLE_DATA_SRC;
+
+ for (size_t k = 0; k < ARRAY_SIZE(extra_mem_stypes); k++) {
+ u64 st = base_stype | extra_mem_stypes[k];
+
+ if (try_open_mem_evlist(evlist, base_attr, pid, cpu,
+ flags, working_p, st)) {
+ pmu->probed.mem_sample_types |= extra_mem_stypes[k];
+ }
+ }
+ }
+
+ evlist__put(evlist);
+ }
+}
+
+static void probe_mmap_caps(struct perf_pmu *pmu,
+ const struct perf_event_attr *base_attr,
+ int pmu_cpu, pid_t pid, int cpu,
+ unsigned long flags)
+{
+ struct perf_event_attr attr = *base_attr;
+ struct perf_event_mmap_page *pc;
+ long page_sz = sysconf(_SC_PAGESIZE);
+ cpu_set_t old_mask, mask;
+ bool affinity_changed = false;
+ bool has_rdpmc_cap = false;
+ int events_fd;
+ int fd = -1;
+
+ pmu->probed.rdpmc_sysfs = -1;
+
+ if (page_sz <= 0)
+ page_sz = 4096;
+
+ events_fd = perf_pmu__event_source_devices_fd();
+ if (events_fd >= 0) {
+ int pmu_dirfd = openat(events_fd, pmu->name, O_DIRECTORY | O_RDONLY | O_CLOEXEC);
+
+ if (pmu_dirfd >= 0) {
+ if (faccessat(pmu_dirfd, "rdpmc", F_OK, 0) == 0) {
+ int rfd;
+
+ has_rdpmc_cap = true;
+ rfd = openat(pmu_dirfd, "rdpmc", O_RDONLY | O_CLOEXEC);
+ if (rfd >= 0) {
+ char rbuf[16];
+ ssize_t n = read(rfd, rbuf, sizeof(rbuf) - 1);
+
+ if (n > 0) {
+ rbuf[n] = '\0';
+ pmu->probed.rdpmc_sysfs = atoi(rbuf);
+ }
+ close(rfd);
+ }
+ }
+ close(pmu_dirfd);
+ }
+ close(events_fd);
+ }
+
+ if (pmu_cpu >= 0 && pmu_cpu < CPU_SETSIZE &&
+ sched_getaffinity(0, sizeof(old_mask), &old_mask) == 0) {
+ CPU_ZERO(&mask);
+ CPU_SET(pmu_cpu, &mask);
+ if (sched_setaffinity(0, sizeof(mask), &mask) == 0)
+ affinity_changed = true;
+ }
+
+ attr.disabled = 0;
+
+ /*
+ * On architectures such as arm64, user-space counter reading must be
+ * explicitly requested via format/rdpmc (config1:1).
+ */
+ if (perf_pmu__has_format(pmu, "rdpmc")) {
+ struct perf_event_attr r_attr = attr;
+ int uval;
+
+ has_rdpmc_cap = true;
+ if (pmu->probed.rdpmc_sysfs < 0 &&
+ sysctl__read_int("kernel/perf_user_access", &uval) == 0)
+ pmu->probed.rdpmc_sysfs = uval;
+
+ r_attr.config1 |= 0x2;
+ fd = sys_perf_event_open(&r_attr, 0, -1, -1, flags);
+ }
+
+ if (fd < 0 && !pmu->is_uncore)
+ fd = sys_perf_event_open(&attr, 0, -1, -1, flags);
+ if (fd < 0)
+ fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
+
+ if (fd >= 0) {
+ pc = mmap(NULL, page_sz, PROT_READ, MAP_SHARED, fd, 0);
+ if (pc != MAP_FAILED) {
+ if (has_rdpmc_cap || pc->cap_user_rdpmc) {
+ pmu->probed.rdpmc_available = true;
+ pmu->probed.pmc_width = pc->pmc_width;
+ }
+ if (pc->cap_user_rdpmc && pc->index != 0) {
+ struct perf_mmap map = { .base = pc };
+ struct perf_counts_values start = { .val = 0 };
+ struct perf_counts_values end = { .val = 0 };
+
+ pmu->probed.can_user_rdpmc = true;
+ if (perf_mmap__read_self(&map, &start) == 0) {
+ for (int spin = 0; spin < 10000; spin++)
+ barrier();
+ if (perf_mmap__read_self(&map, &end) == 0 &&
+ end.val >= start.val && end.val > 0)
+ pmu->probed.rdpmc_works = true;
+ }
+ }
+ pmu->probed.can_user_time = !!pc->cap_user_time;
+ pmu->probed.can_user_time_zero = !!pc->cap_user_time_zero;
+ pmu->probed.can_user_time_short = !!pc->cap_user_time_short;
+ munmap(pc, page_sz);
+ }
+ close(fd);
+ }
+
+ if (affinity_changed)
+ sched_setaffinity(0, sizeof(old_mask), &old_mask);
+}
+
+static bool run_skid_branch_loop(u64 iters, uintptr_t *out_s_ip,
+ uintptr_t *out_b_ip, uintptr_t *out_e_ip,
+ int *out_insn_sz, int *out_nop_cnt)
+{
+#if defined(__x86_64__)
+ uintptr_t s_ip, b_ip, e_ip;
+
+ asm volatile(
+ "lea 1f(%%rip), %[s_ip]\n\t"
+ "lea 2f(%%rip), %[b_ip]\n\t"
+ "lea 3f(%%rip), %[e_ip]\n\t"
+ ".balign 64\n"
+ "1:\n\t"
+ ".rept 8192\n\t"
+ "nop\n\t"
+ ".endr\n\t"
+ "dec %[cnt]\n\t"
+ "2:\n\t"
+ "jnz 1b\n"
+ "3:\n\t"
+ : [cnt] "+r" (iters),
+ [s_ip] "=&r" (s_ip),
+ [b_ip] "=&r" (b_ip),
+ [e_ip] "=&r" (e_ip)
+ :
+ : "cc", "memory"
+ );
+ *out_s_ip = s_ip;
+ *out_b_ip = b_ip;
+ *out_e_ip = e_ip;
+ *out_insn_sz = 1;
+ *out_nop_cnt = 8192;
+ return true;
+#elif defined(__aarch64__)
+ uintptr_t s_ip, b_ip, e_ip;
+
+ asm volatile(
+ "adr %[s_ip], 1f\n\t"
+ "adr %[b_ip], 2f\n\t"
+ "adr %[e_ip], 3f\n\t"
+ ".balign 64\n"
+ "1:\n\t"
+ ".rept 8192\n\t"
+ "nop\n\t"
+ ".endr\n\t"
+ "subs %[cnt], %[cnt], #1\n\t"
+ "2:\n\t"
+ "b.ne 1b\n"
+ "3:\n\t"
+ : [cnt] "+r" (iters),
+ [s_ip] "=&r" (s_ip),
+ [b_ip] "=&r" (b_ip),
+ [e_ip] "=&r" (e_ip)
+ :
+ : "cc", "memory"
+ );
+ *out_s_ip = s_ip;
+ *out_b_ip = b_ip;
+ *out_e_ip = e_ip;
+ *out_insn_sz = 4;
+ *out_nop_cnt = 8192;
+ return true;
+#elif defined(__riscv)
+ uintptr_t s_ip, b_ip, e_ip;
+
+ asm volatile(
+ ".option push\n\t"
+ ".option norvc\n\t"
+ "la %[s_ip], 1f\n\t"
+ "la %[b_ip], 2f\n\t"
+ "la %[e_ip], 3f\n\t"
+ ".balign 64\n"
+ "1:\n\t"
+ ".rept 1000\n\t"
+ "nop\n\t"
+ ".endr\n\t"
+ "addi %[cnt], %[cnt], -1\n\t"
+ "2:\n\t"
+ "bnez %[cnt], 1b\n"
+ "3:\n\t"
+ ".option pop\n\t"
+ : [cnt] "+r" (iters),
+ [s_ip] "=&r" (s_ip),
+ [b_ip] "=&r" (b_ip),
+ [e_ip] "=&r" (e_ip)
+ :
+ : "memory"
+ );
+ *out_s_ip = s_ip;
+ *out_b_ip = b_ip;
+ *out_e_ip = e_ip;
+ *out_insn_sz = 4;
+ *out_nop_cnt = 1000;
+ return true;
+#else
+ (void)iters;
+ *out_s_ip = 0;
+ *out_b_ip = 0;
+ *out_e_ip = 0;
+ *out_insn_sz = 0;
+ *out_nop_cnt = 0;
+ return false;
+#endif
+}
+
+static void probe_pmu_skid(struct perf_pmu *pmu,
+ const struct perf_event_attr *base_attr,
+ int pmu_cpu, unsigned long flags)
+{
+ struct perf_event_attr br_attr;
+ char br_buf[256];
+ long page_sz = sysconf(_SC_PAGESIZE);
+ size_t data_sz, mmap_sz;
+ cpu_set_t old_mask, mask;
+ bool affinity_changed = false;
+
+ if (!pmu->is_core || !pmu->probed.can_sample)
+ return;
+
+ if (page_sz <= 0)
+ page_sz = 4096;
+ data_sz = 4 * (size_t)page_sz;
+ mmap_sz = (size_t)page_sz + data_sz;
+
+ memset(&br_attr, 0, sizeof(br_attr));
+ snprintf(br_buf, sizeof(br_buf), "%s/branches/", pmu->name);
+ if (!parse_candidate_attr(br_buf, &br_attr)) {
+ br_attr.type = PERF_TYPE_HARDWARE;
+ br_attr.size = base_attr->size;
+ br_attr.config = PERF_COUNT_HW_BRANCH_INSTRUCTIONS;
+ if (perf_pmus__supports_extended_type())
+ br_attr.config |= (__u64)pmu->type << PERF_PMU_TYPE_SHIFT;
+ }
+ br_attr.exclude_user = base_attr->exclude_user;
+ br_attr.exclude_kernel = 1;
+ br_attr.exclude_hv = 1;
+ br_attr.exclude_idle = base_attr->exclude_idle;
+ br_attr.exclude_host = base_attr->exclude_host;
+ br_attr.exclude_guest = base_attr->exclude_guest;
+
+ if (pmu_cpu >= 0 && pmu_cpu < CPU_SETSIZE &&
+ sched_getaffinity(0, sizeof(old_mask), &old_mask) == 0) {
+ CPU_ZERO(&mask);
+ CPU_SET(pmu_cpu, &mask);
+ if (sched_setaffinity(0, sizeof(mask), &mask) == 0)
+ affinity_changed = true;
+ }
+
+ for (int lvl = 0; lvl <= 3; lvl++) {
+ struct perf_event_attr attr = br_attr;
+ struct perf_event_mmap_page *pc;
+ uintptr_t s_ip = 0, b_ip = 0, e_ip = 0;
+ int insn_sz = 0, nop_cnt = 0;
+ void *ring;
+ u8 *data;
+ u64 head, tail = 0;
+ int samples = 0, exact = 0;
+ int min_skid = 999999, max_skid = 0;
+ long sum_skid = 0;
+ int fd;
+
+ if (lvl > 0 && !(pmu->probed.precise_mask & (1u << lvl)))
+ continue;
+
+ attr.disabled = 1;
+ attr.sample_period = 251;
+ attr.sample_type = PERF_SAMPLE_IP;
+ attr.precise_ip = lvl;
+
+ fd = sys_perf_event_open(&attr, 0, -1, -1, flags);
+ if (fd < 0 && lvl > 0 && attr.exclude_kernel && attr.config2 == 0) {
+ attr.config2 = 1;
+ fd = sys_perf_event_open(&attr, 0, -1, -1, flags);
+ }
+ if (fd < 0)
+ continue;
+
+ ring = mmap(NULL, mmap_sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+ if (ring == MAP_FAILED) {
+ close(fd);
+ continue;
+ }
+
+ ioctl(fd, PERF_EVENT_IOC_RESET, 0);
+ ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
+ if (!run_skid_branch_loop(8000, &s_ip, &b_ip, &e_ip,
+ &insn_sz, &nop_cnt)) {
+ ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
+ munmap(ring, mmap_sz);
+ close(fd);
+ break;
+ }
+ ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
+
+ pc = ring;
+ head = READ_ONCE(pc->data_head);
+ /* Ensure data_head is read before reading ring buffer contents. */
+ rmb();
+ if (head > data_sz)
+ head = data_sz;
+ data = (u8 *)ring + page_sz;
+
+ while (tail + sizeof(struct perf_event_header) <= head) {
+ struct perf_event_header *hdr =
+ (struct perf_event_header *)(data + tail);
+
+ if (hdr->size == 0 || tail + hdr->size > head)
+ break;
+ if (hdr->type == PERF_RECORD_SAMPLE &&
+ hdr->size >= sizeof(*hdr) + sizeof(u64)) {
+ u64 ip = *(u64 *)((u8 *)hdr + sizeof(*hdr));
+ uintptr_t uip = (uintptr_t)ip;
+
+ if (uip >= s_ip && uip <= e_ip && insn_sz > 0) {
+ int skid;
+
+ if (uip == b_ip) {
+ skid = 0;
+ } else if (uip >= s_ip && uip < b_ip) {
+ long off = (long)(uip - s_ip) / insn_sz;
+
+ skid = (off < nop_cnt) ?
+ (int)(off + 1) : (nop_cnt + 1);
+ } else {
+ skid = 1;
+ }
+
+ samples++;
+ if (hdr->misc & PERF_RECORD_MISC_EXACT_IP)
+ exact++;
+ if (skid < min_skid)
+ min_skid = skid;
+ if (skid > max_skid)
+ max_skid = skid;
+ sum_skid += skid;
+ }
+ }
+ tail += hdr->size;
+ }
+
+ if (samples > 0) {
+ pmu->probed.skid[lvl].measured = true;
+ pmu->probed.skid[lvl].samples = samples;
+ pmu->probed.skid[lvl].exact_samples = exact;
+ pmu->probed.skid[lvl].min_skid = min_skid;
+ pmu->probed.skid[lvl].max_skid = max_skid;
+ pmu->probed.skid[lvl].avg_skid = (double)sum_skid / samples;
+ }
+
+ munmap(ring, mmap_sz);
+ close(fd);
+ }
+
+ if (affinity_changed)
+ sched_setaffinity(0, sizeof(old_mask), &old_mask);
+}
+
+void perf_pmu__probe(struct perf_pmu *pmu)
+{
+ struct probe_candidates cands = { .nr = 0 };
+ struct perf_event_attr base_attr;
+ struct perf_event_attr group_attrs[MAX_PROBE_GROUP_SIZE];
+ char uprobe_exe_path[PATH_MAX];
+ __u64 uprobe_offset = 0;
+ size_t nr_group_attrs = 0;
+ unsigned long flags = perf_event_open_cloexec_flag();
+ int keepalive_fd = -1;
+ int pmu_cpu;
+ pid_t pid = 0;
+ int cpu = 0;
+ int last_err = 0;
+ bool found = false;
+
+ if (!pmu || pmu->probed.checked)
+ return;
+ if (perf_pmu__kind(pmu) != PERF_PMU_KIND_PE)
+ return;
+
+ pmu->probed.checked = true;
+ pmu_cpu = select_probe_cpu(pmu);
+
+ if (pmu->type == PERF_TYPE_TRACEPOINT) {
+ static const struct {
+ const char *sys;
+ const char *name;
+ } fast_tps[] = {
+ { "sched", "sched_switch" },
+ { "raw_syscalls", "sys_enter" },
+ { "irq", "irq_handler_entry" },
+ };
+
+ for (size_t i = 0; i < ARRAY_SIZE(fast_tps); i++) {
+ int tp_id = tp_pmu__id(fast_tps[i].sys, fast_tps[i].name);
+
+ if (tp_id >= 0) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = PERF_TYPE_TRACEPOINT;
+ base_attr.config = tp_id;
+ if (try_open_attr_variants(&base_attr, false, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ char tp_buf[128];
+
+ snprintf(tp_buf, sizeof(tp_buf), "%s:%s",
+ fast_tps[i].sys, fast_tps[i].name);
+ pmu->probed.probe_event = strdup(tp_buf);
+ found = true;
+ break;
+ }
+ }
+ }
+ if (!found) {
+ perf_pmu__for_each_event(pmu, /*skip_duplicate_pmus=*/false,
+ &cands, collect_probe_candidate_cb);
+ }
+ } else if (pmu->name && !strcmp(pmu->name, "kprobe")) {
+ static const char * const kprobe_funcs[] = {
+ "vfs_read",
+ "schedule",
+ "do_sys_openat2",
+ };
+
+ for (size_t i = 0; i < ARRAY_SIZE(kprobe_funcs); i++) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = pmu->type;
+ base_attr.size = sizeof(base_attr);
+ base_attr.kprobe_func = (uintptr_t)kprobe_funcs[i];
+ base_attr.probe_offset = 0;
+ if (try_open_attr_variants(&base_attr, false, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ char kp_buf[128];
+
+ snprintf(kp_buf, sizeof(kp_buf), "kprobe:%s",
+ kprobe_funcs[i]);
+ pmu->probed.probe_event = strdup(kp_buf);
+ found = true;
+ break;
+ }
+ }
+ } else if (pmu->name && !strcmp(pmu->name, "uprobe")) {
+ if (get_self_uprobe_target(uprobe_exe_path, &uprobe_offset)) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = pmu->type;
+ base_attr.size = sizeof(base_attr);
+ base_attr.uprobe_path = (uintptr_t)uprobe_exe_path;
+ base_attr.probe_offset = uprobe_offset;
+ if (try_open_attr_variants(&base_attr, false, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ const char *slash = strrchr(uprobe_exe_path, '/');
+ const char *bname = slash ? slash + 1 : uprobe_exe_path;
+
+ if (asprintf(&pmu->probed.probe_event, "uprobe:%s+0x%llx",
+ bname, (unsigned long long)uprobe_offset) < 0)
+ pmu->probed.probe_event = NULL;
+ found = true;
+ }
+ }
+ } else if (pmu->is_core) {
+ static const char * const core_events[] = {
+ "cycles",
+ "instructions",
+ "branches",
+ "branch-misses",
+ "cache-misses",
+ "cache-references",
+ "bus-cycles",
+ "ref-cycles",
+ };
+ char buf[256];
+
+ for (size_t i = 0; i < ARRAY_SIZE(core_events); i++) {
+ snprintf(buf, sizeof(buf), "%s/%s/", pmu->name, core_events[i]);
+ probe_candidates__add(&cands, buf);
+ }
+ perf_pmu__for_each_event(pmu, /*skip_duplicate_pmus=*/false,
+ &cands, collect_probe_candidate_cb);
+ } else if (pmu->type == PERF_TYPE_SOFTWARE) {
+ static const char * const sw_events[] = {
+ "software/cpu-clock/",
+ "software/task-clock/",
+ "software/page-faults/",
+ "software/context-switches/",
+ "software/cpu-migrations/",
+ "software/minor-faults/",
+ "software/major-faults/",
+ "software/dummy/",
+ };
+
+ for (size_t i = 0; i < ARRAY_SIZE(sw_events); i++)
+ probe_candidates__add(&cands, sw_events[i]);
+ } else if (pmu->type != PERF_TYPE_BREAKPOINT) {
+ if (pmu->selectable) {
+ char buf[256];
+
+ if (perf_pmu__has_format(pmu, "swfilt")) {
+ snprintf(buf, sizeof(buf), "%s/swfilt=1/", pmu->name);
+ probe_candidates__add(&cands, buf);
+ }
+ snprintf(buf, sizeof(buf), "%s//", pmu->name);
+ probe_candidates__add(&cands, buf);
+ }
+ perf_pmu__for_each_event(pmu, /*skip_duplicate_pmus=*/false,
+ &cands, collect_probe_candidate_cb);
+ }
+
+ for (size_t i = 0; !found && i < cands.nr; i++) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ if (!parse_candidate_attr(cands.names[i], &base_attr))
+ continue;
+
+ if (try_open_attr_variants(&base_attr, pmu->is_uncore, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ pmu->probed.probe_event = strdup(cands.names[i]);
+ found = true;
+ break;
+ }
+ }
+
+ if (!found && pmu->is_core) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = PERF_TYPE_HARDWARE;
+ base_attr.config = PERF_COUNT_HW_CPU_CYCLES;
+ if (perf_pmus__supports_extended_type())
+ base_attr.config |= (__u64)pmu->type << PERF_PMU_TYPE_SHIFT;
+ if (try_open_attr_variants(&base_attr, false, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ pmu->probed.probe_event = strdup("cycles");
+ found = true;
+ }
+ }
+
+ if (!found && pmu->type == PERF_TYPE_BREAKPOINT) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = PERF_TYPE_BREAKPOINT;
+ base_attr.bp_addr = (unsigned long)&dummy_bp_var;
+ base_attr.bp_type = HW_BREAKPOINT_W;
+ base_attr.bp_len = HW_BREAKPOINT_LEN_4;
+ if (try_open_attr_variants(&base_attr, false, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ pmu->probed.probe_event = strdup("mem:<addr>:w");
+ found = true;
+ }
+ }
+
+ if (!found && cands.nr == 0) {
+ memset(&base_attr, 0, sizeof(base_attr));
+ base_attr.type = pmu->type;
+ base_attr.size = sizeof(base_attr);
+ if (pmu->perf_event_attr_init_default)
+ pmu->perf_event_attr_init_default(pmu, &base_attr);
+ if (try_open_attr_variants(&base_attr, pmu->is_uncore, pmu_cpu,
+ flags, &pid, &cpu, &last_err)) {
+ char buf[256];
+
+ snprintf(buf, sizeof(buf), "%s//", pmu->name);
+ pmu->probed.probe_event = strdup(buf);
+ found = true;
+ }
+ }
+
+ if (!found) {
+ probe_candidates__exit(&cands);
+ pmu->probed.open_supported = false;
+ pmu->probed.open_err = last_err ?: ENOENT;
+ return;
+ }
+
+ pmu->probed.open_supported = true;
+
+ /*
+ * For tracepoint events, closing the last fd for a tracepoint triggers
+ * tracepoint_synchronize_unregister() (an RCU grace period) in the
+ * kernel. Hold one disabled fd open across the probe sequence so
+ * tp_event->perf_refcount stays >= 1 and each probe open/close is
+ * instantaneous.
+ */
+ if (pmu->type == PERF_TYPE_TRACEPOINT) {
+ struct perf_event_attr ka_attr = base_attr;
+
+ ka_attr.disabled = 1;
+ keepalive_fd = sys_perf_event_open(&ka_attr, pid, cpu, -1, flags);
+ }
+
+ group_attrs[nr_group_attrs++] = base_attr;
+
+ for (size_t i = 0; pmu->type != PERF_TYPE_TRACEPOINT &&
+ i < cands.nr && nr_group_attrs < MAX_PROBE_GROUP_SIZE; i++) {
+ struct perf_event_attr cand_attr;
+ int fd;
+ bool dup = false;
+
+ memset(&cand_attr, 0, sizeof(cand_attr));
+ if (!parse_candidate_attr(cands.names[i], &cand_attr))
+ continue;
+
+ cand_attr.sample_period = base_attr.sample_period;
+ cand_attr.freq = base_attr.freq;
+ cand_attr.sample_type = base_attr.sample_type;
+ cand_attr.exclude_user = base_attr.exclude_user;
+ cand_attr.exclude_kernel = base_attr.exclude_kernel;
+ cand_attr.exclude_hv = base_attr.exclude_hv;
+ cand_attr.exclude_idle = base_attr.exclude_idle;
+ cand_attr.exclude_host = base_attr.exclude_host;
+ cand_attr.exclude_guest = base_attr.exclude_guest;
+ cand_attr.disabled = 1;
+
+ for (size_t j = 0; j < nr_group_attrs; j++) {
+ if (group_attrs[j].type == cand_attr.type &&
+ group_attrs[j].config == cand_attr.config &&
+ group_attrs[j].config1 == cand_attr.config1 &&
+ group_attrs[j].config2 == cand_attr.config2) {
+ dup = true;
+ break;
+ }
+ }
+ if (dup)
+ continue;
+
+ fd = sys_perf_event_open(&cand_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ group_attrs[nr_group_attrs++] = cand_attr;
+ }
+ }
+
+ probe_candidates__exit(&cands);
+
+ /* 1. Counting vs Sampling support */
+ if (base_attr.sample_period == 0) {
+ struct perf_event_attr samp_attr = base_attr;
+ int fd;
+
+ pmu->probed.can_count = true;
+ samp_attr.sample_period = 10000;
+ samp_attr.sample_type = PERF_SAMPLE_IP;
+ fd = sys_perf_event_open(&samp_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_sample = true;
+ }
+ } else {
+ pmu->probed.can_count = false;
+ pmu->probed.can_sample = true;
+ }
+
+ /* 2. All enum perf_event_sample_format types */
+ if (pmu->probed.can_sample)
+ probe_sample_types(pmu, &base_attr, pid, cpu, flags);
+
+ /*
+ * 3. Precise sampling support (:p, :pp, :ppp).
+ * PMUs that do not validate attr.precise_ip (such as software,
+ * breakpoint, or intel_pt) silently accept precise_ip > 0 even when
+ * sample_period == 0. A PMU that genuinely implements precise_ip
+ * either rejects precise_ip > 0 on non-sampling events or is a
+ * sampling-only PMU (such as AMD ibs_op).
+ * Note: On AMD, core events like cycles:P are forwarded to IBS and
+ * support higher precision than advertised in sysfs caps/max_precise.
+ */
+ if (pmu->probed.can_sample && !pmu->auxtrace) {
+ bool ignores_precise_ip = false;
+
+ if (pmu->probed.can_count) {
+ struct perf_event_attr c_attr = base_attr;
+ int fd;
+
+ c_attr.sample_period = 0;
+ c_attr.freq = 0;
+ c_attr.sample_type = 0;
+ c_attr.precise_ip = 1;
+ fd = sys_perf_event_open(&c_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ ignores_precise_ip = true;
+ }
+ }
+
+ if (!ignores_precise_ip) {
+ for (int level = 1; level <= 3; level++) {
+ struct perf_event_attr p_attr = base_attr;
+ int fd;
+
+ p_attr.sample_period = 10000;
+ p_attr.sample_type = PERF_SAMPLE_IP;
+ p_attr.precise_ip = level;
+ fd = sys_perf_event_open(&p_attr, pid, cpu, -1, flags);
+ if (fd < 0 && p_attr.exclude_kernel && p_attr.config2 == 0) {
+ p_attr.config2 = 1;
+ fd = sys_perf_event_open(&p_attr, pid, cpu, -1, flags);
+ }
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.precise_mask |= (1u << level);
+ pmu->probed.max_precise = level;
+ }
+ }
+ }
+
+ probe_pmu_skid(pmu, &base_attr, pmu_cpu, flags);
+ }
+
+ /* 3b. User and interrupt register sampling masks */
+ if (pmu->probed.sample_types & PERF_SAMPLE_REGS_USER) {
+ probe_pmu_regs_one(pmu, &base_attr, pid, cpu, flags,
+ pmu->probed.max_precise, /*intr=*/false,
+ &pmu->probed.user_regs_mask,
+ &pmu->probed.user_regs_abi,
+ &pmu->probed.user_simd_mask,
+ &pmu->probed.user_pred_mask);
+ }
+ if (pmu->probed.sample_types & PERF_SAMPLE_REGS_INTR) {
+ probe_pmu_regs_one(pmu, &base_attr, pid, cpu, flags,
+ pmu->probed.max_precise, /*intr=*/true,
+ &pmu->probed.intr_regs_mask,
+ &pmu->probed.intr_regs_abi,
+ &pmu->probed.intr_simd_mask,
+ &pmu->probed.intr_pred_mask);
+ }
+
+ /* 3c. Memory event types and memory sample formats */
+ probe_mem_events(pmu, &base_attr, pid, cpu, flags);
+
+ /* 4. Privilege / exclusion modifiers */
+ pmu->probed.exclude_user =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_USER);
+ pmu->probed.exclude_kernel =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_KERNEL);
+ pmu->probed.exclude_hv =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_HV);
+ pmu->probed.exclude_idle =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_IDLE);
+ pmu->probed.exclude_host =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_HOST);
+ pmu->probed.exclude_guest =
+ test_exclude_flag(&base_attr, pid, cpu, flags, PROBE_EXCLUDE_GUEST);
+
+ /* 5. Execution features */
+ if (pmu->probed.can_sample) {
+ struct perf_event_attr l_attr = base_attr;
+ struct perf_event_attr f_attr = nr_group_attrs > 1 ? group_attrs[1] : base_attr;
+ int l_fd;
+
+ l_attr.disabled = 1;
+ l_attr.sample_period = 10000;
+ l_attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
+ l_attr.read_format = PERF_FORMAT_GROUP | PERF_FORMAT_ID;
+
+ f_attr.disabled = 0;
+ f_attr.sample_period = 0;
+ f_attr.sample_type = 0;
+ f_attr.read_format = 0;
+
+ l_fd = sys_perf_event_open(&l_attr, pid, cpu, -1, flags);
+ if (l_fd >= 0) {
+ int f_fd = sys_perf_event_open(&f_attr, pid, cpu, l_fd, flags);
+
+ if (f_fd >= 0) {
+ if (ioctl(l_fd, PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) >= 0)
+ pmu->probed.can_leader_sampling = true;
+ ioctl(l_fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP);
+ close(f_fd);
+ }
+ close(l_fd);
+ }
+ }
+
+ {
+ struct perf_event_attr l_attr = base_attr;
+ int l_fd;
+
+ l_attr.disabled = 1;
+ l_fd = sys_perf_event_open(&l_attr, pid, cpu, -1, flags);
+ if (l_fd >= 0) {
+ struct perf_event_attr sw_attr;
+ int sw_fd;
+
+ memset(&sw_attr, 0, sizeof(sw_attr));
+ sw_attr.type = PERF_TYPE_SOFTWARE;
+ sw_attr.size = sizeof(sw_attr);
+ sw_attr.config = PERF_COUNT_SW_DUMMY;
+ sw_attr.disabled = 0;
+ sw_attr.exclude_user = base_attr.exclude_user;
+ sw_attr.exclude_kernel = base_attr.exclude_kernel;
+ sw_attr.exclude_hv = base_attr.exclude_hv;
+ sw_attr.exclude_idle = base_attr.exclude_idle;
+ sw_attr.exclude_host = base_attr.exclude_host;
+ sw_attr.exclude_guest = base_attr.exclude_guest;
+
+ sw_fd = sys_perf_event_open(&sw_attr, pid, cpu, l_fd, flags);
+ if (sw_fd < 0) {
+ sw_attr.config = PERF_COUNT_SW_CPU_CLOCK;
+ sw_fd = sys_perf_event_open(&sw_attr, pid, cpu, l_fd, flags);
+ }
+ if (sw_fd >= 0) {
+ pmu->probed.can_sw_grouping = true;
+ close(sw_fd);
+ }
+ close(l_fd);
+ }
+ }
+
+ {
+ struct perf_event_attr inh_attr = base_attr;
+ int fd;
+
+ inh_attr.disabled = 1;
+ inh_attr.inherit = 1;
+ fd = sys_perf_event_open(&inh_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_inherit = true;
+ }
+ }
+
+ if (pmu->probed.can_sample) {
+ struct perf_event_attr freq_attr = base_attr;
+ int fd;
+
+ freq_attr.disabled = 1;
+ freq_attr.freq = 1;
+ freq_attr.sample_freq = 4000;
+ freq_attr.sample_type = PERF_SAMPLE_IP;
+ fd = sys_perf_event_open(&freq_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_freq = true;
+ }
+ }
+
+ if (pmu->probed.can_sample) {
+ struct perf_event_attr wb_attr = base_attr;
+ int fd;
+
+ wb_attr.disabled = 1;
+ wb_attr.sample_period = 10000;
+ wb_attr.sample_type = PERF_SAMPLE_IP;
+ wb_attr.write_backward = 1;
+ fd = sys_perf_event_open(&wb_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_write_backward = true;
+ }
+ }
+
+ {
+ struct perf_event_attr pin_attr = base_attr;
+ int fd;
+
+ pin_attr.disabled = 1;
+ pin_attr.pinned = 1;
+ fd = sys_perf_event_open(&pin_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_pinned = true;
+ }
+ }
+
+ {
+ struct perf_event_attr exc_attr = base_attr;
+ int fd;
+
+ exc_attr.disabled = 1;
+ exc_attr.exclusive = 1;
+ fd = sys_perf_event_open(&exc_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_exclusive = true;
+ }
+ }
+
+ {
+ struct perf_event_attr lost_attr = base_attr;
+ int fd;
+
+ lost_attr.disabled = 1;
+ lost_attr.read_format = PERF_FORMAT_TOTAL_TIME_ENABLED |
+ PERF_FORMAT_TOTAL_TIME_RUNNING |
+ PERF_FORMAT_LOST;
+ fd = sys_perf_event_open(&lost_attr, pid, cpu, -1, flags);
+ if (fd >= 0) {
+ close(fd);
+ pmu->probed.can_format_lost = true;
+ }
+ }
+
+ /* 5b. User-space mmap capabilities (rdpmc, user_time, pmc_width) */
+ probe_mmap_caps(pmu, &base_attr, pmu_cpu, pid, cpu, flags);
+
+ /* 5c. Auto-counter reload (acr_mask / ratio-to-prev) */
+ if (pmu->probed.can_sample && perf_pmu__has_format(pmu, "acr_mask")) {
+ struct perf_event_attr l_attr = base_attr;
+ struct perf_event_attr f_attr = nr_group_attrs > 1 ? group_attrs[1] : base_attr;
+ int l_fd;
+
+ l_attr.disabled = 1;
+ l_attr.freq = 0;
+ l_attr.sample_period = 200000;
+ l_attr.sample_type = PERF_SAMPLE_IP;
+ l_attr.config2 = 0x2;
+
+ f_attr.disabled = 0;
+ f_attr.freq = 0;
+ f_attr.sample_period = 100000;
+ f_attr.sample_type = PERF_SAMPLE_IP;
+ f_attr.config2 = 0x3;
+
+ l_fd = sys_perf_event_open(&l_attr, pid, cpu, -1, flags);
+ if (l_fd >= 0) {
+ int f_fd = sys_perf_event_open(&f_attr, pid, cpu, l_fd, flags);
+
+ if (f_fd >= 0) {
+ if (ioctl(l_fd, PERF_EVENT_IOC_ENABLE, PERF_IOC_FLAG_GROUP) >= 0)
+ pmu->probed.can_acr = true;
+ ioctl(l_fd, PERF_EVENT_IOC_DISABLE, PERF_IOC_FLAG_GROUP);
+ close(f_fd);
+ }
+ close(l_fd);
+ }
+ }
+
+ /* 5d. AUX area event actions (start_paused, pause, resume, aux_sample) */
+ if (pmu->auxtrace) {
+ struct perf_event_attr a_attr = base_attr;
+ int l_fd;
+
+ a_attr.size = max_t(__u32, base_attr.size, PERF_ATTR_SIZE_VER8);
+ a_attr.disabled = 1;
+ a_attr.aux_start_paused = 1;
+ l_fd = sys_perf_event_open(&a_attr, pid, cpu, -1, flags);
+ if (l_fd >= 0) {
+ close(l_fd);
+ pmu->probed.can_aux_start_paused = true;
+ }
+
+ a_attr = base_attr;
+ a_attr.disabled = 1;
+ l_fd = sys_perf_event_open(&a_attr, pid, cpu, -1, flags);
+ if (l_fd >= 0) {
+ struct perf_event_attr f_attr;
+ int f_fd;
+
+ memset(&f_attr, 0, sizeof(f_attr));
+ f_attr.type = PERF_TYPE_SOFTWARE;
+ f_attr.size = max_t(__u32, base_attr.size, PERF_ATTR_SIZE_VER8);
+ f_attr.config = PERF_COUNT_SW_CPU_CLOCK;
+ f_attr.sample_period = 10000;
+ f_attr.sample_type = PERF_SAMPLE_IP;
+ f_attr.exclude_user = base_attr.exclude_user;
+ f_attr.exclude_kernel = base_attr.exclude_kernel;
+ f_attr.exclude_hv = base_attr.exclude_hv;
+ f_attr.exclude_idle = base_attr.exclude_idle;
+ f_attr.exclude_host = base_attr.exclude_host;
+ f_attr.exclude_guest = base_attr.exclude_guest;
+
+ f_attr.aux_pause = 1;
+ f_attr.aux_resume = 0;
+ f_fd = sys_perf_event_open(&f_attr, pid, cpu, l_fd, flags);
+ if (f_fd >= 0) {
+ close(f_fd);
+ pmu->probed.can_aux_pause = true;
+ }
+
+ f_attr.aux_pause = 0;
+ f_attr.aux_resume = 1;
+ f_fd = sys_perf_event_open(&f_attr, pid, cpu, l_fd, flags);
+ if (f_fd >= 0) {
+ close(f_fd);
+ pmu->probed.can_aux_resume = true;
+ }
+
+ f_attr.aux_resume = 0;
+ f_attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_AUX;
+ f_attr.aux_sample_size = 64;
+ f_fd = sys_perf_event_open(&f_attr, pid, cpu, l_fd, flags);
+ if (f_fd >= 0) {
+ close(f_fd);
+ pmu->probed.can_aux_sample = true;
+ }
+
+ close(l_fd);
+ }
+ }
+
+ /* 6. Max event group size & max simultaneously active group size */
+ if (pmu->name && (!strcmp(pmu->name, "kprobe") || !strcmp(pmu->name, "uprobe"))) {
+ if (pmu->probed.can_leader_sampling || pmu->probed.can_sw_grouping) {
+ pmu->probed.max_group_size = MAX_PROBE_GROUP_SIZE;
+ pmu->probed.max_group_capped = true;
+ pmu->probed.max_active_group_size = MAX_PROBE_GROUP_SIZE;
+ pmu->probed.max_active_capped = true;
+ } else {
+ pmu->probed.max_group_size = 1;
+ pmu->probed.max_active_group_size = 1;
+ }
+ } else {
+ probe_group_limits(group_attrs, nr_group_attrs, pid, cpu, flags,
+ &pmu->probed.max_group_size,
+ &pmu->probed.max_group_capped,
+ &pmu->probed.max_active_group_size,
+ &pmu->probed.max_active_capped);
+ }
+
+ /*
+ * On core PMUs, cycles/instructions may use fixed counters in addition
+ * to general-purpose (GP) programmable counters. Probe a GP-only event
+ * group rotating through distinct GP events to determine the GP limit.
+ */
+ if (pmu->is_core) {
+ static const char * const gp_events[] = {
+ "branches",
+ "branch-misses",
+ "cache-misses",
+ "cache-references",
+ "bus-cycles",
+ "stalled-cycles-frontend",
+ "stalled-cycles-backend",
+ "ref-cycles",
+ };
+ static const int gp_configs[] = {
+ PERF_COUNT_HW_BRANCH_INSTRUCTIONS,
+ PERF_COUNT_HW_BRANCH_MISSES,
+ PERF_COUNT_HW_CACHE_MISSES,
+ PERF_COUNT_HW_CACHE_REFERENCES,
+ PERF_COUNT_HW_BUS_CYCLES,
+ PERF_COUNT_HW_STALLED_CYCLES_FRONTEND,
+ PERF_COUNT_HW_STALLED_CYCLES_BACKEND,
+ PERF_COUNT_HW_REF_CPU_CYCLES,
+ };
+ struct perf_event_attr gp_attrs[MAX_PROBE_GROUP_SIZE];
+ size_t nr_gp_attrs = 0;
+ pid_t gp_pid = pid;
+ int gp_cpu = cpu;
+ int gp_err = 0;
+
+ for (size_t i = 0;
+ i < ARRAY_SIZE(gp_events) && nr_gp_attrs < MAX_PROBE_GROUP_SIZE; i++) {
+ char gp_buf[256];
+ struct perf_event_attr gp_attr;
+ bool parsed;
+
+ snprintf(gp_buf, sizeof(gp_buf), "%s/%s/", pmu->name, gp_events[i]);
+ memset(&gp_attr, 0, sizeof(gp_attr));
+ parsed = parse_candidate_attr(gp_buf, &gp_attr);
+ if (!parsed) {
+ gp_attr.type = PERF_TYPE_HARDWARE;
+ gp_attr.config = gp_configs[i];
+ if (perf_pmus__supports_extended_type())
+ gp_attr.config |= (__u64)pmu->type << PERF_PMU_TYPE_SHIFT;
+ }
+ gp_attr.sample_period = base_attr.sample_period;
+ gp_attr.freq = base_attr.freq;
+ gp_attr.sample_type = base_attr.sample_type;
+ gp_attr.exclude_user = base_attr.exclude_user;
+ gp_attr.exclude_kernel = base_attr.exclude_kernel;
+ gp_attr.exclude_hv = base_attr.exclude_hv;
+ gp_attr.exclude_idle = base_attr.exclude_idle;
+ gp_attr.exclude_host = base_attr.exclude_host;
+ gp_attr.exclude_guest = base_attr.exclude_guest;
+ gp_attr.disabled = 1;
+
+ if (nr_gp_attrs == 0) {
+ if (try_open_attr_variants(&gp_attr, false, pmu_cpu,
+ flags, &gp_pid, &gp_cpu, &gp_err)) {
+ gp_attrs[nr_gp_attrs++] = gp_attr;
+ }
+ } else {
+ int fd = sys_perf_event_open(&gp_attr, gp_pid, gp_cpu, -1, flags);
+
+ if (fd >= 0) {
+ close(fd);
+ gp_attrs[nr_gp_attrs++] = gp_attr;
+ }
+ }
+ }
+
+ if (nr_gp_attrs > 0) {
+ probe_group_limits(gp_attrs, nr_gp_attrs, gp_pid, gp_cpu, flags,
+ &pmu->probed.max_gp_group_size,
+ &pmu->probed.max_gp_group_capped,
+ &pmu->probed.max_active_gp_group_size,
+ &pmu->probed.max_active_gp_capped);
+ }
+ }
+
+ if (keepalive_fd >= 0)
+ close(keepalive_fd);
+}
+
const char *perf_pmu__name_from_config(struct perf_pmu *pmu, u64 config)
{
struct hashmap_entry *entry;
diff --git a/tools/perf/util/pmu.h b/tools/perf/util/pmu.h
index 2c8916ad073e..fe8a90752396 100644
--- a/tools/perf/util/pmu.h
+++ b/tools/perf/util/pmu.h
@@ -207,6 +207,138 @@ struct perf_pmu {
* @mem_events: List of the supported mem events
*/
struct perf_mem_event *mem_events;
+
+ /**
+ * @probed: Capabilities discovered by probing perf_event_open() on live
+ * systems.
+ */
+ struct {
+ /** @checked: Has perf_pmu__probe() been run on this PMU? */
+ bool checked;
+ /** @open_supported: Could a probe event be opened on this PMU? */
+ bool open_supported;
+ /** @can_count: Supports counting (sample_period == 0). */
+ bool can_count;
+ /** @can_sample: Supports interrupt-based sampling (sample_period > 0). */
+ bool can_sample;
+ /** @can_branch_stack: Supports PERF_SAMPLE_BRANCH_STACK. */
+ bool can_branch_stack;
+ /** @can_leader_sampling: Supports group leader sampling (:S). */
+ bool can_leader_sampling;
+ /** @can_sw_grouping: Supports grouping software events with this PMU's events. */
+ bool can_sw_grouping;
+ /** @can_inherit: Supports perf_event_attr::inherit across child tasks. */
+ bool can_inherit;
+ /** @can_freq: Supports dynamic sample frequency (perf_event_attr::freq). */
+ bool can_freq;
+ /** @can_write_backward: Supports overwrite ring buffer (write_backward). */
+ bool can_write_backward;
+ /** @can_callchain: Supports PERF_SAMPLE_CALLCHAIN. */
+ bool can_callchain;
+ /** @can_data_src: Supports PERF_SAMPLE_DATA_SRC. */
+ bool can_data_src;
+ /** @can_weight: Supports PERF_SAMPLE_WEIGHT. */
+ bool can_weight;
+ /** @can_pinned: Supports perf_event_attr::pinned. */
+ bool can_pinned;
+ /** @can_exclusive: Supports perf_event_attr::exclusive. */
+ bool can_exclusive;
+ /** @can_format_lost: Supports PERF_FORMAT_LOST. */
+ bool can_format_lost;
+ /** @can_acr: Supports auto-counter reload (acr_mask / ratio-to-prev). */
+ bool can_acr;
+ /** @can_aux_start_paused: Supports aux_start_paused (PERF_PMU_CAP_AUX_PAUSE). */
+ bool can_aux_start_paused;
+ /** @can_aux_pause: Supports aux_pause action on group followers. */
+ bool can_aux_pause;
+ /** @can_aux_resume: Supports aux_resume action on group followers. */
+ bool can_aux_resume;
+ /** @can_aux_sample: Supports AUX area snapshot sampling (aux_sample_size). */
+ bool can_aux_sample;
+ /** @rdpmc_available: PMU supports user-space counter reading (rdpmc/mrs/csrr). */
+ bool rdpmc_available;
+ /** @can_user_rdpmc: User-space counter reading enabled (cap_user_rdpmc & index). */
+ bool can_user_rdpmc;
+ /** @rdpmc_works: User-space counter read instruction executed and worked. */
+ bool rdpmc_works;
+ /** @can_user_time: Supports user-space time conversion (cap_user_time). */
+ bool can_user_time;
+ /** @can_user_time_zero: Supports cap_user_time_zero in mmap page. */
+ bool can_user_time_zero;
+ /** @can_user_time_short: Supports cap_user_time_short in mmap page. */
+ bool can_user_time_short;
+ /** @exclude_user: Supports perf_event_attr::exclude_user. */
+ bool exclude_user;
+ /** @exclude_kernel: Supports perf_event_attr::exclude_kernel. */
+ bool exclude_kernel;
+ /** @exclude_hv: Supports perf_event_attr::exclude_hv. */
+ bool exclude_hv;
+ /** @exclude_idle: Supports perf_event_attr::exclude_idle. */
+ bool exclude_idle;
+ /** @exclude_host: Supports perf_event_attr::exclude_host. */
+ bool exclude_host;
+ /** @exclude_guest: Supports perf_event_attr::exclude_guest. */
+ bool exclude_guest;
+ /** @max_group_capped: Was max_group_size capped at probe limit? */
+ bool max_group_capped;
+ /** @max_active_capped: Was max_active_group_size capped at probe limit? */
+ bool max_active_capped;
+ /** @max_gp_group_capped: Was max_gp_group_size capped at probe limit? */
+ bool max_gp_group_capped;
+ /** @max_active_gp_capped: Was max_active_gp_group_size capped at probe limit? */
+ bool max_active_gp_capped;
+ /** @probe_event: Name of the event used to probe the PMU. */
+ char *probe_event;
+ /** @open_err: errno if open_supported is false. */
+ int open_err;
+ /** @max_precise: Maximum precise_ip level (0..3) supported. */
+ int max_precise;
+ /** @precise_mask: Bitmask of supported precise_ip levels (1..3). */
+ unsigned int precise_mask;
+ /** @max_group_size: Max events in a group accepted by perf_event_open(). */
+ int max_group_size;
+ /** @max_active_group_size: Max events in a group active simultaneously. */
+ int max_active_group_size;
+ /** @max_gp_group_size: Max GP events in a group accepted by perf_event_open(). */
+ int max_gp_group_size;
+ /** @max_active_gp_group_size: Max GP events in a group active simultaneously. */
+ int max_active_gp_group_size;
+ /** @user_regs_abi: ABI flags for user_regs_mask. */
+ int user_regs_abi;
+ /** @intr_regs_abi: ABI flags for intr_regs_mask. */
+ int intr_regs_abi;
+ /** @rdpmc_sysfs: Value from sysfs rdpmc or perf_user_access (-1 if unknown). */
+ int rdpmc_sysfs;
+ /** @mem_events_mask: Bitmask of memory event types verified by probing. */
+ unsigned int mem_events_mask;
+ /** @pmc_width: Bit-width of hardware counter for user-space rdpmc. */
+ u16 pmc_width;
+ /** @sample_types: Bitmask of supported enum perf_event_sample_format flags. */
+ u64 sample_types;
+ /** @mem_sample_types: Bitmask of memory sample formats verified on mem_events. */
+ u64 mem_sample_types;
+ /** @user_regs_mask: Bitmask of supported sample_regs_user registers. */
+ u64 user_regs_mask;
+ /** @intr_regs_mask: Bitmask of supported sample_regs_intr registers. */
+ u64 intr_regs_mask;
+ /** @user_simd_mask: Bitmask of supported user SIMD vector register classes. */
+ u64 user_simd_mask;
+ /** @user_pred_mask: Bitmask of supported user SIMD predicate register classes. */
+ u64 user_pred_mask;
+ /** @intr_simd_mask: Bitmask of supported intr SIMD vector register classes. */
+ u64 intr_simd_mask;
+ /** @intr_pred_mask: Bitmask of supported intr SIMD predicate register classes. */
+ u64 intr_pred_mask;
+ /** @skid: Measured branch instruction skid at precise_ip levels (0..3). */
+ struct {
+ bool measured;
+ int samples;
+ int exact_samples;
+ int min_skid;
+ int max_skid;
+ double avg_skid;
+ } skid[4];
+ } probed;
};
struct perf_pmu_info {
@@ -329,8 +461,9 @@ bool pmu_uncore_identifier_match(const char *compat, const char *id);
int perf_pmu__convert_scale(const char *scale, char **end, double *sval);
struct perf_pmu_caps *perf_pmu__get_cap(struct perf_pmu *pmu, const char *name);
-
+int perf_pmu__add_cap(struct perf_pmu *pmu, const char *name, const char *value);
int perf_pmu__caps_parse(struct perf_pmu *pmu);
+void perf_pmu__probe(struct perf_pmu *pmu);
void perf_pmu__warn_invalid_config(struct perf_pmu *pmu, __u64 config,
const char *name, int config_num,
diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
index 1355b317f3ed..44f24e3a177a 100644
--- a/tools/perf/util/pmus.c
+++ b/tools/perf/util/pmus.c
@@ -7,13 +7,16 @@
#include <subcmd/pager.h>
#include <sys/types.h>
#include <ctype.h>
+#include <errno.h>
#include <pthread.h>
+#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "cpumap.h"
#include "debug.h"
#include "drm_pmu.h"
+#include "env.h"
#include "evsel.h"
#include "pmus.h"
#include "pmu.h"
@@ -452,7 +455,7 @@ struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const c
return NULL;
}
-static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
+struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
{
bool use_core_pmus = !pmu || pmu->is_core;
int last_pmu_name_len = 0;
@@ -489,6 +492,27 @@ static struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu)
return NULL;
}
+size_t perf_pmu__num_duplicates(const struct perf_pmu *pmu)
+{
+ const struct perf_pmu *pos = pmu;
+ size_t base_len;
+ size_t count = 1;
+
+ if (!pmu || pmu->is_core)
+ return 1;
+
+ base_len = pmu_name_len_no_suffix(pmu->name ?: "");
+ list_for_each_entry_continue(pos, &other_pmus, list) {
+ size_t pos_len = pmu_name_len_no_suffix(pos->name ?: "");
+
+ if (pos_len != base_len ||
+ strncmp(pmu->name ?: "", pos->name ?: "", base_len))
+ break;
+ count++;
+ }
+ return count;
+}
+
struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat)
{
if (!pmu) {
@@ -916,3 +940,198 @@ struct perf_pmu *perf_pmus__fake_pmu(void)
return &fake;
}
+
+static bool env_is_pmu_core(const char *name, struct perf_env *env)
+{
+ if (!strcmp(name, "cpu") || !strcmp(name, "cpum_cf") ||
+ !strcmp(name, "default_core") || strstarts(name, "cpu_") ||
+ strstarts(name, "armv") ||
+ (strstarts(name, "apple_") && strstr(name, "_pmu")))
+ return true;
+
+ if (env && env->hybrid_nodes) {
+ for (int i = 0; i < env->nr_hybrid_nodes; i++) {
+ const char *pmu_name = env->hybrid_nodes[i].pmu_name;
+
+ if (pmu_name && !strcmp(name, pmu_name))
+ return true;
+ }
+ return false;
+ }
+
+ if (!env || !strcmp(perf_env__arch(env), perf_env__arch(NULL)))
+ return is_pmu_core(name);
+
+ return false;
+}
+
+static struct perf_pmu *env_pmu_find_or_add(const char *name, __u32 type,
+ struct perf_env *env,
+ const struct pmu_events_table *core_table)
+{
+ struct perf_pmu *pmu = pmu_find(name);
+
+ if (pmu) {
+ if (pmu->type == PERF_PMU_TYPE_FAKE && type != PERF_PMU_TYPE_FAKE)
+ pmu->type = type;
+ return pmu;
+ }
+
+ pmu = zalloc(sizeof(*pmu));
+ if (!pmu)
+ return NULL;
+
+ if (perf_pmu__init(pmu, type, name) != 0) {
+ perf_pmu__delete(pmu);
+ return NULL;
+ }
+
+ pmu->sysfs_aliases_loaded = true;
+ pmu->caps_initialized = true;
+ pmu->max_precise = -1;
+ pmu->is_core = env_is_pmu_core(name, env);
+ pmu->is_uncore = strstarts(name, "uncore_");
+
+ if (!strcmp(name, "software") || !strcmp(name, "tool"))
+ pmu->events_table = perf_pmu__default_core_events_table();
+ else if (core_table && (pmu->is_core || pmu->is_uncore))
+ pmu->events_table = core_table;
+
+ list_add_tail(&pmu->list, pmu->is_core ? &core_pmus : &other_pmus);
+ return pmu;
+}
+
+static void env_pmu_add_caps_strings(struct perf_pmu *pmu, int nr_caps, char **caps)
+{
+ if (!pmu || nr_caps <= 0 || !caps)
+ return;
+
+ for (int i = 0; i < nr_caps; i++) {
+ const char *eq;
+
+ if (!caps[i])
+ continue;
+ eq = strchr(caps[i], '=');
+
+ if (eq) {
+ char *key = strndup(caps[i], eq - caps[i]);
+
+ if (key) {
+ perf_pmu__add_cap(pmu, key, eq + 1);
+ free(key);
+ }
+ } else {
+ perf_pmu__add_cap(pmu, caps[i], "");
+ }
+ }
+}
+
+int perf_pmus__read_from_env(struct perf_env *env)
+{
+ const struct pmu_events_table *core_table = NULL;
+ struct perf_pmu *pmu;
+
+ if (!env)
+ return -EINVAL;
+
+ perf_pmus__destroy();
+ read_pmu_types = PERF_TOOL_PMU_TYPE_ALL_MASK;
+
+ if (env->cpuid) {
+ char cpuid_str[128];
+ char vendor[32];
+ unsigned int family, model, step;
+ const char *cpuid = env->cpuid;
+
+ /*
+ * x86 HEADER_CPUID stores "vendor,family,model,step" in decimal
+ * while pmu-events tables match "vendor-family-HEXMODEL-HEXSTEP".
+ */
+ if (sscanf(env->cpuid, "%31[^,],%u,%u,%u",
+ vendor, &family, &model, &step) == 4) {
+ snprintf(cpuid_str, sizeof(cpuid_str), "%s-%u-%X-%X",
+ vendor, family, model, step);
+ cpuid = cpuid_str;
+ }
+ core_table = find_core_events_table(perf_env__arch(env), cpuid);
+ }
+
+ /* 1. Populate from HEADER_PMU_MAPPINGS */
+ if (env->nr_pmu_mappings > 0 && env->pmu_mappings) {
+ char *str = env->pmu_mappings;
+
+ for (int i = 0; i < env->nr_pmu_mappings; i++) {
+ char *colon = NULL;
+ unsigned long type = strtoul(str, &colon, 0);
+
+ if (!colon || *colon != ':')
+ break;
+ str = colon + 1;
+ env_pmu_find_or_add(str, (__u32)type, env, core_table);
+ str += strlen(str) + 1;
+ }
+ }
+
+ /* 2. Populate/enrich from HEADER_HYBRID_TOPOLOGY */
+ for (int i = 0; i < env->nr_hybrid_nodes; i++) {
+ struct hybrid_node *hn = &env->hybrid_nodes[i];
+
+ if (!hn->pmu_name)
+ continue;
+ pmu = env_pmu_find_or_add(hn->pmu_name, PERF_PMU_TYPE_FAKE,
+ env, core_table);
+ if (!pmu)
+ continue;
+ if (!pmu->is_core) {
+ pmu->is_core = true;
+ if (!pmu->events_table && core_table)
+ pmu->events_table = core_table;
+ list_move_tail(&pmu->list, &core_pmus);
+ }
+ if (hn->cpus && !pmu->cpus)
+ pmu->cpus = perf_cpu_map__new(hn->cpus);
+ }
+
+ /*
+ * 3. Populate/enrich from HEADER_CPU_PMU_CAPS.
+ * On hybrid systems HEADER_CPU_PMU_CAPS duplicates the first core PMU
+ * while HEADER_PMU_CAPS has the per-PMU capabilities, so only create a
+ * "cpu" PMU entry if no core PMUs exist yet.
+ */
+ if (env->nr_cpu_pmu_caps > 0 && env->cpu_pmu_caps) {
+ pmu = pmu_find("cpu");
+ if (!pmu && list_empty(&core_pmus)) {
+ pmu = env_pmu_find_or_add("cpu", PERF_TYPE_RAW,
+ env, core_table);
+ }
+ if (pmu)
+ env_pmu_add_caps_strings(pmu, env->nr_cpu_pmu_caps, env->cpu_pmu_caps);
+ }
+
+ /* 4. Populate/enrich from HEADER_PMU_CAPS */
+ for (int i = 0; i < env->nr_pmus_with_caps; i++) {
+ struct pmu_caps *pc = &env->pmu_caps[i];
+
+ if (!pc->pmu_name)
+ continue;
+ pmu = env_pmu_find_or_add(pc->pmu_name, PERF_PMU_TYPE_FAKE,
+ env, core_table);
+ if (pmu)
+ env_pmu_add_caps_strings(pmu, pc->nr_caps, pc->caps);
+ }
+
+ /* 5. Set default core CPUs on non-hybrid systems */
+ if (env->nr_cpus_avail > 0 && env->nr_hybrid_nodes == 0) {
+ char buf[64];
+
+ snprintf(buf, sizeof(buf), "0-%d", env->nr_cpus_avail - 1);
+ list_for_each_entry(pmu, &core_pmus, list) {
+ if (!pmu->cpus)
+ pmu->cpus = perf_cpu_map__new(buf);
+ }
+ }
+
+ list_sort(NULL, &core_pmus, pmus_cmp);
+ list_sort(NULL, &other_pmus, pmus_cmp);
+ return 0;
+}
diff --git a/tools/perf/util/pmus.h b/tools/perf/util/pmus.h
index 0d55edb3f2fc..f1402e50b5b9 100644
--- a/tools/perf/util/pmus.h
+++ b/tools/perf/util/pmus.h
@@ -6,6 +6,7 @@
#include <stddef.h>
struct perf_event_attr;
+struct perf_env;
struct perf_pmu;
struct print_callbacks;
@@ -14,16 +15,19 @@ size_t pmu_name_len_no_suffix(const char *str);
int pmu_name_cmp(const char *lhs_pmu_name, const char *rhs_pmu_name);
void perf_pmus__destroy(void);
+int perf_pmus__read_from_env(struct perf_env *env);
struct perf_pmu *perf_pmus__find(const char *name);
struct perf_pmu *perf_pmus__find_by_type(unsigned int type);
struct perf_pmu *perf_pmus__find_by_attr(const struct perf_event_attr *attr);
struct perf_pmu *perf_pmus__scan(struct perf_pmu *pmu);
+struct perf_pmu *perf_pmus__scan_skip_duplicates(struct perf_pmu *pmu);
struct perf_pmu *perf_pmus__scan_core(struct perf_pmu *pmu);
struct perf_pmu *perf_pmus__scan_for_event(struct perf_pmu *pmu, const char *event);
struct perf_pmu *perf_pmus__scan_matching_wildcard(struct perf_pmu *pmu, const char *wildcard);
struct perf_pmu *perf_pmus__scan_for_uncore_id(struct perf_pmu *pmu, const char *compat);
+size_t perf_pmu__num_duplicates(const struct perf_pmu *pmu);
const struct perf_pmu *perf_pmus__pmu_for_pmu_filter(const char *str);
--
2.56.0.212.g129ede20d9-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test
2026-10-16 21:32 [RFC PATCH v1 0/2] perf sysinfo: Add subcommand to probe and summarize PMU capabilities Ian Rogers
2026-10-16 21:32 ` [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing Ian Rogers
@ 2026-10-16 21:32 ` Ian Rogers
2026-10-16 21:45 ` sashiko-bot
1 sibling, 1 reply; 5+ messages in thread
From: Ian Rogers @ 2026-10-16 21:32 UTC (permalink / raw)
To: Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo,
Namhyung Kim, Jiri Olsa, Ian Rogers, Adrian Hunter, James Clark
Cc: linux-perf-users, linux-kernel, Stephane Eranian
Add the 'perf sysinfo' subcommand to display and probe PMUs and system
performance monitoring capabilities on the running system or from a
perf.data file.
For each PMU, 'perf sysinfo' reports static attributes (type,
core/uncore/software/auxtrace/drm/hwmon/tool classification, CPUs,
capabilities, sysfs formats, event counts, and memory profiling events)
as well as probed runtime capabilities in text or JSON format, followed
by a system-wide summary of core features, memory and PCIe/IO bus
bandwidth monitoring, total events and metrics, pipeline metric
drill-down levels, and an overall system rating.
Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/Build | 1 +
tools/perf/Documentation/perf-sysinfo.txt | 109 ++
tools/perf/Documentation/perf.txt | 2 +-
tools/perf/builtin-help.c | 3 +-
tools/perf/builtin-sysinfo.c | 1958 +++++++++++++++++++++
tools/perf/builtin.h | 1 +
tools/perf/perf.c | 1 +
tools/perf/tests/shell/sysinfo.sh | 71 +
8 files changed, 2144 insertions(+), 2 deletions(-)
create mode 100644 tools/perf/Documentation/perf-sysinfo.txt
create mode 100644 tools/perf/builtin-sysinfo.c
create mode 100755 tools/perf/tests/shell/sysinfo.sh
diff --git a/tools/perf/Build b/tools/perf/Build
index dcba5ba55206..8a3f6071fa40 100644
--- a/tools/perf/Build
+++ b/tools/perf/Build
@@ -13,6 +13,7 @@ perf-y += builtin-list.o
perf-y += builtin-record.o
perf-y += builtin-report.o
perf-y += builtin-stat.o
+perf-y += builtin-sysinfo.o
perf-y += builtin-top.o
perf-y += builtin-script.o
perf-y += builtin-kvm.o
diff --git a/tools/perf/Documentation/perf-sysinfo.txt b/tools/perf/Documentation/perf-sysinfo.txt
new file mode 100644
index 000000000000..4fc5fe229060
--- /dev/null
+++ b/tools/perf/Documentation/perf-sysinfo.txt
@@ -0,0 +1,109 @@
+perf-sysinfo(1)
+===============
+
+NAME
+----
+perf-sysinfo - Display and probe PMU and system performance monitoring information
+
+SYNOPSIS
+--------
+[verse]
+'perf sysinfo' [<options>] [pmu_glob ...]
+
+DESCRIPTION
+-----------
+This command displays a summary of the performance monitoring capabilities of
+the current system or a perf.data file, including core PMU features (precise
+sampling, branch stack sampling, user-space counter reading, memory profiling,
+and hardware AUX trace PMUs), memory and PCIe/IO interconnect bus bandwidth
+monitoring support, total events and metrics, pipeline metric drill-down levels
+discovered via '<metric>_group' hierarchies, and an overall system rating.
+
+When '-p'/'--pmus' is specified (or when PMU filter globs, '-v'/'--verbose',
+'-a'/'--all', or '-j'/'--json' are given), it also displays detailed
+information for each PMU, including its perf_event_attr type, kind (core,
+uncore, software, auxtrace, tool, hwmon, drm), CPUs/cpumask, capabilities,
+sysfs format bitfields, event counts, and memory profiling events.
+
+When run on a live system (without '-i'/'--input' and with probing enabled),
+it also actively probes the kernel via 'perf_event_open' to determine:
+- Supported modes (counting, interrupt-based sampling, branch_stack sampling)
+- Supported precise sampling levels, skid semantics, and empirically measured
+ branch instruction skid (minimum, maximum, average instructions from the
+ branch and 'PERF_RECORD_MISC_EXACT_IP' ratio) at each supported precision
+ level:
+ 0 ('SAMPLE_IP' can have arbitrary skid), ':p' / 1 ('SAMPLE_IP' must have
+ constant skid), ':pp' / 2 ('SAMPLE_IP' requested to have 0 skid), and
+ ':ppp' / 3 ('SAMPLE_IP' must have 0 skid, or uses randomization to avoid
+ sample shadowing effects)
+- Supported 'perf_event_sample_format' sample types ('ip', 'tid', 'time',
+ 'addr', 'read', 'callchain', 'id', 'cpu', 'period', 'stream_id', 'raw',
+ 'branch_stack', 'regs_user', 'stack_user', 'weight', 'data_src',
+ 'identifier', 'transaction', 'regs_intr', 'phys_addr', 'aux', 'cgroup',
+ 'data_page_size', 'code_page_size', 'weight_struct')
+- Supported user and interrupt registers for 'PERF_SAMPLE_REGS_USER' and
+ 'PERF_SAMPLE_REGS_INTR'
+- Supported memory profiling events ('ldlat-loads', 'ldlat-stores', 'mem-ldst')
+ and their supported memory sample types ('data_src', 'addr', 'weight', etc.)
+- Supported privilege/exclusion modifiers ('exclude_user', 'exclude_kernel',
+ 'exclude_hv', 'exclude_idle', 'exclude_host', 'exclude_guest')
+- Supported execution features ('leader_sampling', 'sw_grouping', 'inherit',
+ 'sample_freq', 'write_backward', 'callchain', 'data_src', 'weight',
+ 'pinned', 'exclusive', 'format_lost', 'auto_counter_reload',
+ 'aux_start_paused', 'aux_pause', 'aux_resume', 'aux_sample', 'user_rdpmc',
+ 'user_time', 'user_time_zero', 'user_time_short') and hardware counter
+ bit-width ('pmc_width') when user-space counter reading is supported
+- Maximum event group size accepted by 'perf_event_open' and maximum
+ simultaneously active counters in a group without multiplexing
+
+At the end of the text output, a summary section reports overall core PMU
+capabilities (including hardware AUX trace PMUs), memory and PCIe/IO
+interconnect bus bandwidth monitoring support, total events and metrics, and
+pipeline metric drill-down levels discovered via '<metric>_group' hierarchies.
+
+By default, numbered uncore PMU instances sharing a common prefix are collapsed
+into a single entry showing the instance count, unless '-v'/'--verbose' is
+specified.
+
+OPTIONS
+-------
+-i::
+--input=::
+ Input file name to read PMU information from (e.g. perf.data).
+
+-f::
+--force::
+ Don't complain, do it (when reading input perf.data file).
+
+-o::
+--output=::
+ Output file name.
+
+-p::
+--pmus::
+ Display detailed information for each PMU in addition to the system
+ summary.
+
+-j::
+--json::
+ Encode PMU information as JSON.
+
+-a::
+--all::
+-v::
+--verbose::
+ Display all PMUs including all similar PMUs with alphanumeric suffixes
+ instead of collapsing numbered uncore PMU instances.
+
+--probe::
+--no-probe::
+ Enable or disable active kernel probing of PMU capabilities on the live
+ system (default: enabled).
+
+--debug::
+ Enable debugging output.
+
+SEE ALSO
+--------
+linkperf:perf-list[1], linkperf:perf-evlist[1], linkperf:perf-stat[1],
+linkperf:perf-record[1]
diff --git a/tools/perf/Documentation/perf.txt b/tools/perf/Documentation/perf.txt
index cbcc2e4d557e..0890dd5a1794 100644
--- a/tools/perf/Documentation/perf.txt
+++ b/tools/perf/Documentation/perf.txt
@@ -92,5 +92,5 @@ linkperf:perf-help[1], linkperf:perf-inject[1],
linkperf:perf-intel-pt[1], linkperf:perf-iostat[1], linkperf:perf-kallsyms[1],
linkperf:perf-kmem[1], linkperf:perf-kvm[1], linkperf:perf-lock[1],
linkperf:perf-mem[1], linkperf:perf-probe[1], linkperf:perf-sched[1],
-linkperf:perf-script[1], linkperf:perf-test[1],
+linkperf:perf-script[1], linkperf:perf-sysinfo[1], linkperf:perf-test[1],
linkperf:perf-trace[1], linkperf:perf-version[1]
diff --git a/tools/perf/builtin-help.c b/tools/perf/builtin-help.c
index 5bbdb4d9b9c0..fbab4b77761b 100644
--- a/tools/perf/builtin-help.c
+++ b/tools/perf/builtin-help.c
@@ -329,6 +329,7 @@ void list_common_cmds_help(void)
{"report", "Read perf.data (created by perf record) and display the profile"},
{"script", "Read perf.data (created by perf record) and display trace output"},
{"stat", "Run a command and gather performance counter statistics"},
+ {"sysinfo", "Display and probe PMU and system performance monitoring information"},
{"test", "Runs sanity tests."},
{"top", "System profiling tool."},
{"version", "display the version of perf binary"},
@@ -485,7 +486,7 @@ int cmd_help(int argc, const char **argv)
};
const char * const builtin_help_subcommands[] = {
"buildid-cache", "buildid-list", "diff", "evlist", "help", "list",
- "record", "report", "bench", "stat", "timechart", "top", "annotate",
+ "record", "report", "bench", "stat", "sysinfo", "timechart", "top", "annotate",
"script", "sched", "kallsyms", "kmem", "lock", "kvm", "test", "inject", "mem", "data",
#ifdef HAVE_LIBELF_SUPPORT
"probe",
diff --git a/tools/perf/builtin-sysinfo.c b/tools/perf/builtin-sysinfo.c
new file mode 100644
index 000000000000..8bc13f3dedb0
--- /dev/null
+++ b/tools/perf/builtin-sysinfo.c
@@ -0,0 +1,1958 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * builtin-sysinfo.c
+ *
+ * Builtin sysinfo command: Display and probe PMU and system performance
+ * monitoring information in a system or a perf.data file.
+ */
+#include "builtin.h"
+
+#include "util/color.h"
+#include "util/cpumap.h"
+#include "util/data.h"
+#include "util/debug.h"
+#include "util/evlist.h"
+#include "util/evsel.h"
+#include "util/header.h"
+#include "util/mem-events.h"
+#include "util/metricgroup.h"
+#include "util/perf_regs.h"
+#include "util/pmu.h"
+#include "util/pmus.h"
+#include "util/session.h"
+#include "util/strbuf.h"
+#include "util/string2.h"
+#include "util/strlist.h"
+#include "util/tool.h"
+
+#include <dwarf-regs.h>
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/err.h>
+#include <linux/perf_event.h>
+#include <linux/zalloc.h>
+#include <subcmd/pager.h>
+#include <subcmd/parse-options.h>
+
+#include <errno.h>
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+
+static const char *pmu_type_desc(u32 type)
+{
+ switch (type) {
+ case PERF_TYPE_HARDWARE:
+ return "PERF_TYPE_HARDWARE";
+ case PERF_TYPE_SOFTWARE:
+ return "PERF_TYPE_SOFTWARE";
+ case PERF_TYPE_TRACEPOINT:
+ return "PERF_TYPE_TRACEPOINT";
+ case PERF_TYPE_HW_CACHE:
+ return "PERF_TYPE_HW_CACHE";
+ case PERF_TYPE_RAW:
+ return "PERF_TYPE_RAW";
+ case PERF_TYPE_BREAKPOINT:
+ return "PERF_TYPE_BREAKPOINT";
+ default:
+ if (type <= PERF_PMU_TYPE_PE_END)
+ return "dynamic";
+ if (type <= PERF_PMU_TYPE_DRM_END)
+ return "drm";
+ if (type <= PERF_PMU_TYPE_HWMON_END)
+ return "hwmon";
+ if (type == PERF_PMU_TYPE_TOOL)
+ return "tool";
+ return "fake";
+ }
+}
+
+static const char *format_config_name(int config)
+{
+ static const char * const config_names[PERF_PMU_FORMAT_VALUE_CONFIG_END] = {
+ [PERF_PMU_FORMAT_VALUE_CONFIG] = "config",
+ [PERF_PMU_FORMAT_VALUE_CONFIG1] = "config1",
+ [PERF_PMU_FORMAT_VALUE_CONFIG2] = "config2",
+ [PERF_PMU_FORMAT_VALUE_CONFIG3] = "config3",
+ [PERF_PMU_FORMAT_VALUE_CONFIG4] = "config4",
+ };
+
+ if (config >= 0 && config < PERF_PMU_FORMAT_VALUE_CONFIG_END)
+ return config_names[config];
+ return "config?";
+}
+
+static bool pmu_matches_filters(const struct perf_pmu *pmu,
+ int argc, const char **argv)
+{
+ if (argc <= 0)
+ return true;
+
+ for (int i = 0; i < argc; i++) {
+ const char *pat = argv[i];
+
+ if (perf_pmu__wildcard_match(pmu, pat))
+ return true;
+ if (pmu->name && (strglobmatch(pmu->name, pat) || !strcmp(pmu->name, pat)))
+ return true;
+ if (pmu->alias_name &&
+ (strglobmatch(pmu->alias_name, pat) || !strcmp(pmu->alias_name, pat)))
+ return true;
+ if (pmu->name) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name);
+
+ if (strlen(pat) == base_len && !strncmp(pmu->name, pat, base_len))
+ return true;
+ }
+ }
+ return false;
+}
+
+static void json_escape_fprintf(FILE *fp, struct strbuf *buf, const char *fmt, ...)
+{
+ va_list args;
+
+ va_start(args, fmt);
+ strbuf_setlen(buf, 0);
+ for (size_t fmt_pos = 0; fmt_pos < strlen(fmt); fmt_pos++) {
+ switch (fmt[fmt_pos]) {
+ case '%':
+ fmt_pos++;
+ switch (fmt[fmt_pos]) {
+ case 's': {
+ const char *s = va_arg(args, const char*);
+
+ strbuf_addstr(buf, s);
+ break;
+ }
+ case 'S': {
+ const char *s = va_arg(args, const char*);
+
+ for (size_t s_pos = 0; s[s_pos] != '\0'; s_pos++) {
+ switch (s[s_pos]) {
+ case '\n':
+ strbuf_addstr(buf, "\\n");
+ break;
+ case '\r':
+ strbuf_addstr(buf, "\\r");
+ break;
+ case '\t':
+ strbuf_addstr(buf, "\\t");
+ break;
+ case '\\':
+ fallthrough;
+ case '\"':
+ strbuf_addch(buf, '\\');
+ fallthrough;
+ default:
+ strbuf_addch(buf, s[s_pos]);
+ break;
+ }
+ }
+ break;
+ }
+ default:
+ strbuf_addch(buf, '%');
+ strbuf_addch(buf, fmt[fmt_pos]);
+ break;
+ }
+ break;
+ default:
+ strbuf_addch(buf, fmt[fmt_pos]);
+ break;
+ }
+ }
+ va_end(args);
+ fputs(buf->buf, fp);
+}
+
+struct print_format_state {
+ FILE *fp;
+ struct strbuf *buf;
+ bool json;
+ int count;
+};
+
+static int print_format_cb(void *vstate, const char *name, int config,
+ const unsigned long *bits)
+{
+ struct print_format_state *state = vstate;
+ char bits_buf[128];
+
+ if (!bits)
+ return 0;
+
+ bitmap_scnprintf((unsigned long *)bits, PERF_PMU_FORMAT_BITS,
+ bits_buf, sizeof(bits_buf));
+
+ if (state->json) {
+ char spec[160];
+
+ if (state->count == 0)
+ fprintf(state->fp, ",\n\t\"Formats\": {\n");
+
+ snprintf(spec, sizeof(spec), "%s:%s",
+ format_config_name(config), bits_buf);
+ json_escape_fprintf(state->fp, state->buf, "%s\t\t\"%S\": \"%S\"",
+ state->count > 0 ? ",\n" : "",
+ name, spec);
+ } else {
+ if (state->count == 0)
+ fprintf(state->fp, " Formats: ");
+
+ fprintf(state->fp, "%s%s (%s:%s)",
+ state->count > 0 ? ", " : "",
+ name, format_config_name(config), bits_buf);
+ }
+ state->count++;
+ return 0;
+}
+
+static bool evsel_matches_pmu(const struct evsel *evsel,
+ const struct perf_pmu *pmu, bool show_all)
+{
+ struct perf_pmu *ev_pmu = evsel__find_pmu(evsel);
+ const char *ev_pmu_name;
+
+ if (ev_pmu == pmu)
+ return true;
+
+ if (ev_pmu) {
+ if (!show_all && !pmu->is_core && pmu->name && ev_pmu->name) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name);
+
+ if (pmu_name_len_no_suffix(ev_pmu->name) == base_len &&
+ !strncmp(pmu->name, ev_pmu->name, base_len))
+ return true;
+ }
+ return false;
+ }
+
+ ev_pmu_name = evsel__pmu_name(evsel);
+ if (ev_pmu_name && pmu->name) {
+ if (!strcmp(ev_pmu_name, pmu->name))
+ return true;
+ if (!show_all && !pmu->is_core) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name);
+
+ if (pmu_name_len_no_suffix(ev_pmu_name) == base_len &&
+ !strncmp(pmu->name, ev_pmu_name, base_len))
+ return true;
+ }
+ }
+ return false;
+}
+
+static void print_recorded_events(FILE *fp, struct strbuf *buf,
+ const struct perf_pmu *pmu,
+ const struct perf_session *session,
+ bool show_all, bool json)
+{
+ struct strlist *ev_names;
+ struct str_node *pos;
+ struct evsel *evsel;
+ size_t count = 0;
+
+ if (!session || !session->evlist)
+ return;
+
+ ev_names = strlist__new(NULL, NULL);
+ if (!ev_names)
+ return;
+
+ evlist__for_each_entry(session->evlist, evsel) {
+ if (evsel_matches_pmu(evsel, pmu, show_all))
+ strlist__add(ev_names, evsel__name(evsel));
+ }
+
+ if (strlist__empty(ev_names)) {
+ strlist__delete(ev_names);
+ return;
+ }
+
+ if (json) {
+ fprintf(fp, ",\n\t\"RecordedEvents\": [");
+ strlist__for_each_entry(pos, ev_names) {
+ json_escape_fprintf(fp, buf, "%s\"%S\"",
+ count > 0 ? ", " : "", pos->s);
+ count++;
+ }
+ fprintf(fp, "]");
+ } else {
+ fprintf(fp, " Recorded events: ");
+ strlist__for_each_entry(pos, ev_names) {
+ fprintf(fp, "%s%s", count > 0 ? ", " : "", pos->s);
+ count++;
+ }
+ fputc('\n', fp);
+ }
+
+ strlist__delete(ev_names);
+}
+
+static const struct {
+ u64 bit;
+ const char *name;
+} sample_type_names[] = {
+ { PERF_SAMPLE_IP, "ip" },
+ { PERF_SAMPLE_TID, "tid" },
+ { PERF_SAMPLE_TIME, "time" },
+ { PERF_SAMPLE_ADDR, "addr" },
+ { PERF_SAMPLE_READ, "read" },
+ { PERF_SAMPLE_CALLCHAIN, "callchain" },
+ { PERF_SAMPLE_ID, "id" },
+ { PERF_SAMPLE_CPU, "cpu" },
+ { PERF_SAMPLE_PERIOD, "period" },
+ { PERF_SAMPLE_STREAM_ID, "stream_id" },
+ { PERF_SAMPLE_RAW, "raw" },
+ { PERF_SAMPLE_BRANCH_STACK, "branch_stack" },
+ { PERF_SAMPLE_REGS_USER, "regs_user" },
+ { PERF_SAMPLE_STACK_USER, "stack_user" },
+ { PERF_SAMPLE_WEIGHT, "weight" },
+ { PERF_SAMPLE_DATA_SRC, "data_src" },
+ { PERF_SAMPLE_IDENTIFIER, "identifier" },
+ { PERF_SAMPLE_TRANSACTION, "transaction" },
+ { PERF_SAMPLE_REGS_INTR, "regs_intr" },
+ { PERF_SAMPLE_PHYS_ADDR, "phys_addr" },
+ { PERF_SAMPLE_AUX, "aux" },
+ { PERF_SAMPLE_CGROUP, "cgroup" },
+ { PERF_SAMPLE_DATA_PAGE_SIZE, "data_page_size" },
+ { PERF_SAMPLE_CODE_PAGE_SIZE, "code_page_size" },
+ { PERF_SAMPLE_WEIGHT_STRUCT, "weight_struct" },
+};
+
+static const char *precise_level_desc(int lvl)
+{
+ switch (lvl) {
+ case 0:
+ return "0 - SAMPLE_IP can have arbitrary skid";
+ case 1:
+ return "1 - SAMPLE_IP must have constant skid";
+ case 2:
+ return "2 - SAMPLE_IP requested to have 0 skid";
+ case 3:
+ return "3 - SAMPLE_IP must have 0 skid, or uses randomization";
+ default:
+ return "unknown";
+ }
+}
+
+static void print_precise_levels(FILE *fp, const struct perf_pmu *pmu,
+ unsigned int precise_mask,
+ int max_precise, bool json)
+{
+ static const char * const pnames[] = { "", ":p", ":pp", ":ppp" };
+ bool need_sep = false;
+
+ if (json) {
+ fprintf(fp, ",\n\t\t\"PreciseLevels\": [");
+ for (int lvl = 1; lvl <= 3; lvl++) {
+ if (precise_mask & (1u << lvl)) {
+ fprintf(fp, "%s\"%s\"",
+ need_sep ? ", " : "", pnames[lvl]);
+ need_sep = true;
+ }
+ }
+ fprintf(fp, "]");
+ return;
+ }
+
+ fprintf(fp, " Precise sampling: ");
+ if (precise_mask == 0) {
+ if (perf_pmu__is_software(pmu)) {
+ color_fprintf(fp, PERF_COLOR_GREEN, "always precise");
+ fprintf(fp, " (software event, SAMPLE_IP has 0 skid)\n");
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "not supported");
+ fprintf(fp, " (%s)\n", precise_level_desc(0));
+ }
+ return;
+ }
+
+ for (int lvl = 1; lvl <= 3; lvl++) {
+ if (precise_mask & (1u << lvl)) {
+ if (need_sep)
+ fprintf(fp, ", ");
+ color_fprintf(fp, PERF_COLOR_GREEN, "%s", pnames[lvl]);
+ fprintf(fp, " (%s)", precise_level_desc(lvl));
+ need_sep = true;
+ }
+ }
+ fprintf(fp, " (max_precise: ");
+ color_fprintf(fp, PERF_COLOR_GREEN, "%d", max_precise);
+ fprintf(fp, ")\n");
+}
+
+static void print_measured_skid(FILE *fp, const struct perf_pmu *pmu, bool json)
+{
+ static const char * const lvl_keys[] = { "0", ":p", ":pp", ":ppp" };
+ static const char * const lvl_labels[] = {
+ "level 0 (no :p)",
+ "level 1 (:p)",
+ "level 2 (:pp)",
+ "level 3 (:ppp)",
+ };
+ const typeof(pmu->probed) *p = &pmu->probed;
+ bool any = false;
+ bool first = true;
+
+ for (int lvl = 0; lvl <= 3; lvl++) {
+ if (p->skid[lvl].measured) {
+ any = true;
+ break;
+ }
+ }
+ if (!any)
+ return;
+
+ if (json)
+ fprintf(fp, ",\n\t\t\"MeasuredSkid\": {\n");
+ else
+ fprintf(fp, " Measured branch skid (instructions from branch):\n");
+
+ for (int lvl = 0; lvl <= 3; lvl++) {
+ if (!p->skid[lvl].measured)
+ continue;
+ if (json) {
+ fprintf(fp,
+ "%s\t\t\t\"%s\": { \"Samples\": %d, \"ExactIp\": %d, \"MinInsn\": %d, \"MaxInsn\": %d, \"AvgInsn\": %.1f }",
+ first ? "" : ",\n",
+ lvl_keys[lvl],
+ p->skid[lvl].samples,
+ p->skid[lvl].exact_samples,
+ p->skid[lvl].min_skid,
+ p->skid[lvl].max_skid,
+ p->skid[lvl].avg_skid);
+ } else {
+ const char *skid_color = PERF_COLOR_YELLOW;
+
+ if (p->skid[lvl].max_skid == 0)
+ skid_color = PERF_COLOR_GREEN;
+ else if (p->skid[lvl].max_skid <= 2)
+ skid_color = PERF_COLOR_CYAN;
+
+ fprintf(fp, " %-15s: ", lvl_labels[lvl]);
+ color_fprintf(fp, skid_color, "min %d, max %d, avg %.1f",
+ p->skid[lvl].min_skid,
+ p->skid[lvl].max_skid,
+ p->skid[lvl].avg_skid);
+ fprintf(fp, " (%d/%d exact_ip)\n",
+ p->skid[lvl].exact_samples,
+ p->skid[lvl].samples);
+ }
+ first = false;
+ }
+
+ if (json)
+ fprintf(fp, "\n\t\t}");
+}
+
+static void print_sample_type_list(FILE *fp, u64 mask, bool json)
+{
+ bool need_sep = false;
+
+ for (size_t x = 0; x < ARRAY_SIZE(sample_type_names); x++) {
+ if (!(mask & sample_type_names[x].bit))
+ continue;
+ if (json)
+ fprintf(fp, "%s\"%s\"", need_sep ? ", " : "", sample_type_names[x].name);
+ else
+ fprintf(fp, "%s%s", need_sep ? ", " : "", sample_type_names[x].name);
+ need_sep = true;
+ }
+ if (!json && !need_sep)
+ fprintf(fp, "none");
+}
+
+static void print_probed_regs(FILE *fp, struct strbuf *buf, const char *label,
+ u64 mask, int abi, u64 simd_mask, u64 pred_mask,
+ bool intr, bool json)
+{
+ const char *last_name = NULL;
+ bool need_sep = false;
+
+ if (!mask && !simd_mask && !pred_mask)
+ return;
+
+ if (json)
+ fprintf(fp, ",\n\t\t\"%s\": [", label);
+ else
+ fprintf(fp, " %s: ", label);
+
+ for (int reg = 0; reg < 64; reg++) {
+ const char *name;
+
+ if (!(mask & BIT_ULL(reg)))
+ continue;
+ name = perf_reg_name(reg, EM_HOST, EF_HOST, abi);
+ if (!name || !strcmp(name, "unknown"))
+ continue;
+ if (last_name && !strcmp(last_name, name))
+ continue;
+ last_name = name;
+
+ if (json) {
+ json_escape_fprintf(fp, buf, "%s\"%S\"",
+ need_sep ? ", " : "", name);
+ } else {
+ fprintf(fp, "%s%s", need_sep ? ", " : "", name);
+ }
+ need_sep = true;
+ }
+
+ for (int is_pred = 0; is_pred <= 1; is_pred++) {
+ bool pred = is_pred != 0;
+ u64 cmask = pred ? pred_mask : simd_mask;
+
+ for (int reg_c = 0; reg_c < 64; reg_c++) {
+ const char *cname;
+ u16 qwords = 0;
+ u64 bitmap;
+ char reg_range[64];
+
+ if (!(cmask & BIT_ULL(reg_c)))
+ continue;
+ cname = perf_simd_reg_class_name(EM_HOST, reg_c, pred);
+ bitmap = intr ?
+ perf_intr_simd_reg_class_bitmap_qwords(EM_HOST, reg_c,
+ &qwords, pred) :
+ perf_user_simd_reg_class_bitmap_qwords(EM_HOST, reg_c,
+ &qwords, pred);
+ if (!cname || !bitmap)
+ continue;
+ snprintf(reg_range, sizeof(reg_range), "%s0-%d",
+ cname, fls64(bitmap) - 1);
+ if (json) {
+ json_escape_fprintf(fp, buf, "%s\"%S\"",
+ need_sep ? ", " : "", reg_range);
+ } else {
+ fprintf(fp, "%s%s", need_sep ? ", " : "", reg_range);
+ }
+ need_sep = true;
+ }
+ }
+
+ if (json)
+ fprintf(fp, "]");
+ else
+ fputc('\n', fp);
+}
+
+static void print_mem_events_static(FILE *fp, struct strbuf *buf,
+ const struct perf_pmu *pmu, bool json)
+{
+ bool first = true;
+
+ if (!pmu->mem_events)
+ return;
+
+ perf_pmu__mem_events_init_pmu((struct perf_pmu *)pmu);
+
+ for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
+ struct perf_mem_event *e = perf_pmu__mem_events_ptr((struct perf_pmu *)pmu, j);
+ char ev_buf[256];
+ const char *s;
+
+ if (!e || !e->tag || !e->supported)
+ continue;
+ s = perf_pmu__mem_events_name((struct perf_pmu *)pmu, j,
+ ev_buf, sizeof(ev_buf));
+ if (!s)
+ continue;
+
+ if (json) {
+ if (first)
+ fprintf(fp, ",\n\t\"MemoryEvents\": {\n");
+ json_escape_fprintf(fp, buf, "%s\t\t\"%S\": \"%S\"",
+ first ? "" : ",\n", e->tag, s);
+ } else {
+ if (first)
+ fprintf(fp, " Memory events: ");
+ fprintf(fp, "%s%s (%s)", first ? "" : ", ", e->tag, s);
+ }
+ first = false;
+ }
+
+ if (!first) {
+ if (json)
+ fprintf(fp, "\n\t}");
+ else
+ fputc('\n', fp);
+ }
+}
+
+static void print_pmu_json(FILE *fp, const struct perf_pmu *pmu,
+ const struct perf_session *session, bool show_all)
+{
+ struct strbuf buf;
+ size_t num_instances = show_all ? 1 : perf_pmu__num_duplicates(pmu);
+ char display_name[128];
+ size_t total_events;
+ struct print_format_state format_state = {
+ .fp = fp,
+ .buf = &buf,
+ .json = true,
+ .count = 0,
+ };
+
+ strbuf_init(&buf, 0);
+
+ if (num_instances > 1) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name ?: "");
+
+ snprintf(display_name, sizeof(display_name), "%.*s",
+ (int)base_len, pmu->name ?: "");
+ } else {
+ snprintf(display_name, sizeof(display_name), "%s", pmu->name ?: "");
+ }
+
+ fprintf(fp, "{\n");
+ json_escape_fprintf(fp, &buf, "\t\"Unit\": \"%S\"", display_name);
+ if (pmu->name)
+ json_escape_fprintf(fp, &buf, ",\n\t\"FullName\": \"%S\"", pmu->name);
+ fprintf(fp, ",\n\t\"Instances\": %zu", num_instances);
+ if (pmu->alias_name)
+ json_escape_fprintf(fp, &buf, ",\n\t\"Alias\": \"%S\"", pmu->alias_name);
+ if (pmu->id)
+ json_escape_fprintf(fp, &buf, ",\n\t\"Identifier\": \"%S\"", pmu->id);
+ if (pmu->type != PERF_PMU_TYPE_FAKE) {
+ fprintf(fp, ",\n\t\"Type\": %u", pmu->type);
+ json_escape_fprintf(fp, &buf, ",\n\t\"TypeDesc\": \"%S\"",
+ pmu_type_desc(pmu->type));
+ }
+ fprintf(fp, ",\n\t\"IsCore\": %s", pmu->is_core ? "true" : "false");
+ fprintf(fp, ",\n\t\"IsUncore\": %s", pmu->is_uncore ? "true" : "false");
+ fprintf(fp, ",\n\t\"IsSoftware\": %s", perf_pmu__is_software(pmu) ? "true" : "false");
+ fprintf(fp, ",\n\t\"Auxtrace\": %s", pmu->auxtrace ? "true" : "false");
+ fprintf(fp, ",\n\t\"Selectable\": %s", pmu->selectable ? "true" : "false");
+
+ if (pmu->cpus) {
+ char cpus_buf[256];
+ int nr_cpus = perf_cpu_map__nr(pmu->cpus);
+
+ cpu_map__snprint(pmu->cpus, cpus_buf, sizeof(cpus_buf));
+ if (cpus_buf[0]) {
+ json_escape_fprintf(fp, &buf, ",\n\t\"CPUs\": \"%S\"", cpus_buf);
+ fprintf(fp, ",\n\t\"NrCPUs\": %d", nr_cpus);
+ }
+ }
+
+ perf_pmu__caps_parse((struct perf_pmu *)pmu);
+ if (!list_empty(&pmu->caps)) {
+ struct perf_pmu_caps *cap;
+ bool first = true;
+
+ fprintf(fp, ",\n\t\"Capabilities\": {\n");
+ list_for_each_entry(cap, &pmu->caps, list) {
+ json_escape_fprintf(fp, &buf, "%s\t\t\"%S\": \"%S\"",
+ first ? "" : ",\n",
+ cap->name, cap->value);
+ first = false;
+ }
+ fprintf(fp, "\n\t}");
+ }
+
+ perf_pmu__for_each_format((struct perf_pmu *)pmu, &format_state, print_format_cb);
+ if (format_state.count > 0)
+ fprintf(fp, "\n\t}");
+
+ total_events = perf_pmu__num_events((struct perf_pmu *)pmu);
+ if (total_events > 0) {
+ size_t sysfs_events = pmu->sysfs_aliases;
+ size_t json_events = total_events > sysfs_events ? total_events - sysfs_events : 0;
+
+ fprintf(fp, ",\n\t\"Events\": {\n");
+ fprintf(fp, "\t\t\"Total\": %zu,\n", total_events);
+ fprintf(fp, "\t\t\"Sysfs\": %zu,\n", sysfs_events);
+ fprintf(fp, "\t\t\"Json\": %zu\n", json_events);
+ fprintf(fp, "\t}");
+ }
+
+ print_mem_events_static(fp, &buf, pmu, /*json=*/true);
+ print_recorded_events(fp, &buf, pmu, session, show_all, /*json=*/true);
+
+ if (pmu->probed.checked) {
+ const typeof(pmu->probed) *p = &pmu->probed;
+
+ fprintf(fp, ",\n\t\"Probed\": {\n");
+ fprintf(fp, "\t\t\"OpenSupported\": %s",
+ p->open_supported ? "true" : "false");
+ if (p->open_supported) {
+ bool need_sep = false;
+ const struct {
+ bool supported;
+ const char *name;
+ } excl[] = {
+ { p->exclude_user, "exclude_user" },
+ { p->exclude_kernel, "exclude_kernel" },
+ { p->exclude_hv, "exclude_hv" },
+ { p->exclude_idle, "exclude_idle" },
+ { p->exclude_host, "exclude_host" },
+ { p->exclude_guest, "exclude_guest" },
+ };
+
+ if (p->probe_event) {
+ json_escape_fprintf(fp, &buf,
+ ",\n\t\t\"ProbeEvent\": \"%S\"",
+ p->probe_event);
+ }
+ fprintf(fp, ",\n\t\t\"Counting\": %s",
+ p->can_count ? "true" : "false");
+ fprintf(fp, ",\n\t\t\"Sampling\": %s",
+ p->can_sample ? "true" : "false");
+ fprintf(fp, ",\n\t\t\"BranchStack\": %s",
+ p->can_branch_stack ? "true" : "false");
+ if (p->can_sample) {
+ if (!pmu->auxtrace) {
+ const char *pdesc = (p->max_precise == 0 &&
+ perf_pmu__is_software(pmu)) ?
+ "software event - SAMPLE_IP has 0 skid" :
+ precise_level_desc(p->max_precise);
+
+ fprintf(fp, ",\n\t\t\"MaxPrecise\": %d", p->max_precise);
+ json_escape_fprintf(fp, &buf,
+ ",\n\t\t\"MaxPreciseDesc\": \"%S\"",
+ pdesc);
+ print_precise_levels(fp, pmu, p->precise_mask,
+ p->max_precise, /*json=*/true);
+
+ print_measured_skid(fp, pmu, /*json=*/true);
+ }
+
+ fprintf(fp, ",\n\t\t\"SampleTypes\": [");
+ print_sample_type_list(fp, p->sample_types, /*json=*/true);
+ fprintf(fp, "]");
+ }
+
+ print_probed_regs(fp, &buf, "UserRegisters",
+ p->user_regs_mask, p->user_regs_abi,
+ p->user_simd_mask, p->user_pred_mask,
+ /*intr=*/false, /*json=*/true);
+ print_probed_regs(fp, &buf, "IntrRegisters",
+ p->intr_regs_mask, p->intr_regs_abi,
+ p->intr_simd_mask, p->intr_pred_mask,
+ /*intr=*/true, /*json=*/true);
+
+ if (p->mem_events_mask) {
+ need_sep = false;
+ fprintf(fp, ",\n\t\t\"MemoryEvents\": [");
+ for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
+ struct perf_mem_event *e =
+ perf_pmu__mem_events_ptr((struct perf_pmu *)pmu, j);
+
+ if (e && e->tag && (p->mem_events_mask & (1u << j))) {
+ json_escape_fprintf(fp, &buf, "%s\"%S\"",
+ need_sep ? ", " : "",
+ e->tag);
+ need_sep = true;
+ }
+ }
+ fprintf(fp, "]");
+
+ fprintf(fp, ",\n\t\t\"MemorySampleTypes\": [");
+ print_sample_type_list(fp, p->mem_sample_types, /*json=*/true);
+ fprintf(fp, "]");
+ }
+
+ need_sep = false;
+ fprintf(fp, ",\n\t\t\"ExcludeModifiers\": [");
+ for (size_t x = 0; x < ARRAY_SIZE(excl); x++) {
+ if (excl[x].supported) {
+ fprintf(fp, "%s\"%s\"",
+ need_sep ? ", " : "",
+ excl[x].name);
+ need_sep = true;
+ }
+ }
+ fprintf(fp, "]");
+
+ {
+ const struct {
+ bool supported;
+ const char *name;
+ } feats[] = {
+ { p->can_leader_sampling, "leader_sampling" },
+ { p->can_sw_grouping, "sw_grouping" },
+ { p->can_inherit, "inherit" },
+ { p->can_freq, "sample_freq" },
+ { p->can_write_backward, "write_backward" },
+ { p->can_callchain, "callchain" },
+ { p->can_data_src, "data_src" },
+ { p->can_weight, "weight" },
+ { p->can_pinned, "pinned" },
+ { p->can_exclusive, "exclusive" },
+ { p->can_format_lost, "format_lost" },
+ { p->can_acr, "auto_counter_reload" },
+ { p->can_aux_start_paused, "aux_start_paused" },
+ { p->can_aux_pause, "aux_pause" },
+ { p->can_aux_resume, "aux_resume" },
+ { p->can_aux_sample, "aux_sample" },
+ { p->can_user_rdpmc, "user_rdpmc" },
+ { p->can_user_time, "user_time" },
+ { p->can_user_time_zero, "user_time_zero" },
+ { p->can_user_time_short, "user_time_short" },
+ };
+
+ need_sep = false;
+ fprintf(fp, ",\n\t\t\"Features\": [");
+ for (size_t x = 0; x < ARRAY_SIZE(feats); x++) {
+ if (feats[x].supported) {
+ fprintf(fp, "%s\"%s\"",
+ need_sep ? ", " : "",
+ feats[x].name);
+ need_sep = true;
+ }
+ }
+ fprintf(fp, "]");
+ }
+
+ if (pmu->auxtrace) {
+ const struct {
+ bool supported;
+ const char *name;
+ } aux_acts[] = {
+ { p->can_aux_start_paused, "aux_start_paused" },
+ { p->can_aux_pause, "aux_pause" },
+ { p->can_aux_resume, "aux_resume" },
+ { p->can_aux_sample, "aux_sample" },
+ };
+
+ need_sep = false;
+ fprintf(fp, ",\n\t\t\"AuxActions\": [");
+ for (size_t x = 0; x < ARRAY_SIZE(aux_acts); x++) {
+ if (aux_acts[x].supported) {
+ fprintf(fp, "%s\"%s\"",
+ need_sep ? ", " : "",
+ aux_acts[x].name);
+ need_sep = true;
+ }
+ }
+ fprintf(fp, "]");
+ }
+
+ if (p->can_user_rdpmc && p->pmc_width > 0)
+ fprintf(fp, ",\n\t\t\"PmcWidth\": %u", p->pmc_width);
+
+ fprintf(fp, ",\n\t\t\"UserRdpmc\": {\n");
+ fprintf(fp, "\t\t\t\"Available\": %s,\n",
+ p->rdpmc_available ? "true" : "false");
+ fprintf(fp, "\t\t\t\"Enabled\": %s,\n",
+ p->can_user_rdpmc ? "true" : "false");
+ fprintf(fp, "\t\t\t\"Working\": %s",
+ p->rdpmc_works ? "true" : "false");
+ if (p->rdpmc_available && p->pmc_width > 0)
+ fprintf(fp, ",\n\t\t\t\"PmcWidth\": %u", p->pmc_width);
+ if (p->rdpmc_sysfs >= 0)
+ fprintf(fp, ",\n\t\t\t\"Sysfs\": %d", p->rdpmc_sysfs);
+ fprintf(fp, "\n\t\t}");
+
+ fprintf(fp, ",\n\t\t\"MaxGroupSize\": %d",
+ p->max_group_size);
+ fprintf(fp, ",\n\t\t\"MaxGroupSizeCapped\": %s",
+ p->max_group_capped ? "true" : "false");
+ fprintf(fp, ",\n\t\t\"MaxActiveGroupSize\": %d",
+ p->max_active_group_size);
+ fprintf(fp, ",\n\t\t\"MaxActiveGroupSizeCapped\": %s",
+ p->max_active_capped ? "true" : "false");
+ if (p->max_gp_group_size > 0) {
+ fprintf(fp, ",\n\t\t\"MaxGpGroupSize\": %d",
+ p->max_gp_group_size);
+ fprintf(fp, ",\n\t\t\"MaxActiveGpGroupSize\": %d",
+ p->max_active_gp_group_size);
+ }
+ } else {
+ json_escape_fprintf(fp, &buf, ",\n\t\t\"Error\": \"%S\"",
+ strerror(p->open_err));
+ }
+ fprintf(fp, "\n\t}");
+ }
+
+ fprintf(fp, "\n}");
+ strbuf_release(&buf);
+}
+
+static void print_pmu_text(FILE *fp, const struct perf_pmu *pmu,
+ const struct perf_session *session, bool show_all)
+{
+ size_t num_instances = show_all ? 1 : perf_pmu__num_duplicates(pmu);
+ char display_name[128];
+ const char *kind_sep = "";
+ size_t total_events;
+ struct print_format_state format_state = {
+ .fp = fp,
+ .buf = NULL,
+ .json = false,
+ .count = 0,
+ };
+
+ if (num_instances > 1) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name ?: "");
+
+ snprintf(display_name, sizeof(display_name), "%.*s",
+ (int)base_len, pmu->name ?: "");
+ } else {
+ snprintf(display_name, sizeof(display_name), "%s", pmu->name ?: "");
+ }
+
+ color_fprintf(fp, PERF_COLOR_BOLD, "%s", display_name);
+ fprintf(fp, " (");
+ if (pmu->type != PERF_PMU_TYPE_FAKE) {
+ fprintf(fp, "type: %u [%s]", pmu->type, pmu_type_desc(pmu->type));
+ kind_sep = ", ";
+ }
+ if (pmu->is_core) {
+ fprintf(fp, "%s", kind_sep);
+ color_fprintf(fp, PERF_COLOR_GREEN, "core");
+ kind_sep = ", ";
+ }
+ if (pmu->is_uncore) {
+ fprintf(fp, "%s", kind_sep);
+ color_fprintf(fp, PERF_COLOR_CYAN, "uncore");
+ kind_sep = ", ";
+ }
+ if (perf_pmu__is_software(pmu)) {
+ fprintf(fp, "%s", kind_sep);
+ color_fprintf(fp, PERF_COLOR_BLUE, "software");
+ kind_sep = ", ";
+ }
+ if (pmu->auxtrace) {
+ fprintf(fp, "%s", kind_sep);
+ color_fprintf(fp, PERF_COLOR_MAGENTA, "auxtrace");
+ kind_sep = ", ";
+ }
+ if (pmu->selectable) {
+ fprintf(fp, "%sselectable", kind_sep);
+ kind_sep = ", ";
+ }
+ fprintf(fp, "):\n");
+
+ if (num_instances > 1 || (pmu->name && strcmp(pmu->name, display_name) != 0))
+ fprintf(fp, " Instances: %zu (first: %s)\n", num_instances, pmu->name);
+ if (pmu->alias_name)
+ fprintf(fp, " Alias: %s\n", pmu->alias_name);
+ if (pmu->id)
+ fprintf(fp, " Identifier: %s\n", pmu->id);
+ if (pmu->cpus) {
+ char cpus_buf[256];
+ int nr_cpus = perf_cpu_map__nr(pmu->cpus);
+
+ cpu_map__snprint(pmu->cpus, cpus_buf, sizeof(cpus_buf));
+ if (cpus_buf[0]) {
+ if (nr_cpus > 0)
+ fprintf(fp, " CPUs: %s (%d %s)\n",
+ cpus_buf, nr_cpus,
+ nr_cpus == 1 ? "CPU" : "CPUs");
+ else
+ fprintf(fp, " CPUs: %s\n", cpus_buf);
+ }
+ }
+
+ perf_pmu__caps_parse((struct perf_pmu *)pmu);
+ if (!list_empty(&pmu->caps)) {
+ struct perf_pmu_caps *cap;
+ bool first = true;
+
+ fprintf(fp, " Capabilities: ");
+ list_for_each_entry(cap, &pmu->caps, list) {
+ fprintf(fp, "%s%s=%s", first ? "" : ", ", cap->name, cap->value);
+ first = false;
+ }
+ fputc('\n', fp);
+ }
+
+ perf_pmu__for_each_format((struct perf_pmu *)pmu, &format_state, print_format_cb);
+ if (format_state.count > 0)
+ fputc('\n', fp);
+
+ total_events = perf_pmu__num_events((struct perf_pmu *)pmu);
+ if (total_events > 0) {
+ size_t sysfs_events = pmu->sysfs_aliases;
+ size_t json_events = total_events > sysfs_events ? total_events - sysfs_events : 0;
+
+ fprintf(fp, " Events: %zu total (%zu sysfs, %zu json)\n",
+ total_events, sysfs_events, json_events);
+ }
+
+ print_mem_events_static(fp, NULL, pmu, /*json=*/false);
+ print_recorded_events(fp, NULL, pmu, session, show_all, /*json=*/false);
+
+ if (pmu->probed.checked) {
+ const typeof(pmu->probed) *p = &pmu->probed;
+
+ if (!p->open_supported) {
+ fprintf(fp, " Probed capabilities: ");
+ if (p->open_err == EACCES && pmu->name &&
+ !strcmp(pmu->name, "kprobe")) {
+ color_fprintf(fp, PERF_COLOR_YELLOW,
+ "unavailable (%s; requires CAP_PERFMON or CAP_SYS_ADMIN)",
+ strerror(p->open_err));
+ } else if (p->open_err == EACCES && pmu->name &&
+ !strcmp(pmu->name, "uprobe")) {
+ color_fprintf(fp, PERF_COLOR_YELLOW,
+ "unavailable (%s; requires CAP_SYS_ADMIN)",
+ strerror(p->open_err));
+ } else {
+ color_fprintf(fp, PERF_COLOR_YELLOW, "unavailable (%s)",
+ strerror(p->open_err));
+ }
+ fputc('\n', fp);
+ } else {
+ const char *sep = "";
+ const struct {
+ bool supported;
+ const char *name;
+ } excl[] = {
+ { p->exclude_user, "exclude_user" },
+ { p->exclude_kernel, "exclude_kernel" },
+ { p->exclude_hv, "exclude_hv" },
+ { p->exclude_idle, "exclude_idle" },
+ { p->exclude_host, "exclude_host" },
+ { p->exclude_guest, "exclude_guest" },
+ };
+
+ fprintf(fp, " Probed capabilities (event: ");
+ color_fprintf(fp, PERF_COLOR_CYAN, "%s",
+ p->probe_event ?: "default");
+ fprintf(fp, "):\n");
+ fprintf(fp, " Modes: ");
+ if (p->can_count) {
+ fprintf(fp, "%s", sep);
+ color_fprintf(fp, PERF_COLOR_GREEN, "counting");
+ sep = ", ";
+ }
+ if (p->can_sample) {
+ fprintf(fp, "%s", sep);
+ color_fprintf(fp, PERF_COLOR_GREEN, "sampling");
+ sep = ", ";
+ }
+ if (p->can_branch_stack) {
+ fprintf(fp, "%s", sep);
+ color_fprintf(fp, PERF_COLOR_GREEN, "branch_stack");
+ sep = ", ";
+ }
+ if (*sep == '\0')
+ color_fprintf(fp, PERF_COLOR_RED, "none");
+ fputc('\n', fp);
+
+ if (p->can_sample) {
+ if (!pmu->auxtrace) {
+ print_precise_levels(fp, pmu, p->precise_mask,
+ p->max_precise, /*json=*/false);
+
+ print_measured_skid(fp, pmu, /*json=*/false);
+ }
+
+ fprintf(fp, " Sample types: ");
+ print_sample_type_list(fp, p->sample_types, /*json=*/false);
+ fputc('\n', fp);
+ }
+
+ print_probed_regs(fp, NULL, "User registers",
+ p->user_regs_mask, p->user_regs_abi,
+ p->user_simd_mask, p->user_pred_mask,
+ /*intr=*/false, /*json=*/false);
+ print_probed_regs(fp, NULL, "Intr registers",
+ p->intr_regs_mask, p->intr_regs_abi,
+ p->intr_simd_mask, p->intr_pred_mask,
+ /*intr=*/true, /*json=*/false);
+
+ if (p->mem_events_mask) {
+ sep = "";
+ fprintf(fp, " Memory events (probed): ");
+ for (int j = 0; j < PERF_MEM_EVENTS__MAX; j++) {
+ struct perf_mem_event *e =
+ perf_pmu__mem_events_ptr((struct perf_pmu *)pmu, j);
+
+ if (e && e->tag && (p->mem_events_mask & (1u << j))) {
+ fprintf(fp, "%s%s", sep, e->tag);
+ sep = ", ";
+ }
+ }
+ if (p->mem_sample_types) {
+ fprintf(fp, " (sample types: ");
+ print_sample_type_list(fp, p->mem_sample_types,
+ /*json=*/false);
+ fprintf(fp, ")");
+ }
+ fputc('\n', fp);
+ }
+
+ sep = "";
+ fprintf(fp, " Exclusion modifiers: ");
+ for (size_t x = 0; x < ARRAY_SIZE(excl); x++) {
+ if (excl[x].supported) {
+ fprintf(fp, "%s%s", sep, excl[x].name);
+ sep = ", ";
+ }
+ }
+ if (*sep == '\0')
+ fprintf(fp, "none");
+ fputc('\n', fp);
+
+ {
+ const struct {
+ bool supported;
+ const char *name;
+ } feats[] = {
+ { p->can_leader_sampling, "leader_sampling" },
+ { p->can_sw_grouping, "sw_grouping" },
+ { p->can_inherit, "inherit" },
+ { p->can_freq, "sample_freq" },
+ { p->can_write_backward, "write_backward" },
+ { p->can_callchain, "callchain" },
+ { p->can_data_src, "data_src" },
+ { p->can_weight, "weight" },
+ { p->can_pinned, "pinned" },
+ { p->can_exclusive, "exclusive" },
+ { p->can_format_lost, "format_lost" },
+ { p->can_acr, "auto_counter_reload" },
+ { p->can_aux_start_paused, "aux_start_paused" },
+ { p->can_aux_pause, "aux_pause" },
+ { p->can_aux_resume, "aux_resume" },
+ { p->can_aux_sample, "aux_sample" },
+ { p->can_user_rdpmc, "user_rdpmc" },
+ { p->can_user_time, "user_time" },
+ { p->can_user_time_zero, "user_time_zero" },
+ { p->can_user_time_short, "user_time_short" },
+ };
+
+ sep = "";
+ fprintf(fp, " Features: ");
+ for (size_t x = 0; x < ARRAY_SIZE(feats); x++) {
+ if (feats[x].supported) {
+ fprintf(fp, "%s%s", sep, feats[x].name);
+ sep = ", ";
+ }
+ }
+ if (*sep == '\0')
+ fprintf(fp, "none");
+ fputc('\n', fp);
+ }
+
+ if (pmu->auxtrace) {
+ const struct {
+ bool supported;
+ const char *name;
+ } aux_acts[] = {
+ { p->can_aux_start_paused, "aux_start_paused" },
+ { p->can_aux_pause, "aux_pause" },
+ { p->can_aux_resume, "aux_resume" },
+ { p->can_aux_sample, "aux_sample" },
+ };
+
+ sep = "";
+ fprintf(fp, " AUX actions: ");
+ for (size_t x = 0; x < ARRAY_SIZE(aux_acts); x++) {
+ if (aux_acts[x].supported) {
+ fprintf(fp, "%s%s", sep, aux_acts[x].name);
+ sep = ", ";
+ }
+ }
+ if (*sep == '\0')
+ fprintf(fp, "none");
+ fputc('\n', fp);
+ }
+
+ if (pmu->is_core || p->rdpmc_available) {
+ fprintf(fp, " User space counter reading (rdpmc): ");
+ if (!p->rdpmc_available) {
+ color_fprintf(fp, PERF_COLOR_RED, "not supported");
+ fputc('\n', fp);
+ } else {
+ color_fprintf(fp, PERF_COLOR_GREEN, "available");
+ fprintf(fp, ", ");
+ color_fprintf(fp,
+ p->can_user_rdpmc ?
+ PERF_COLOR_GREEN : PERF_COLOR_YELLOW,
+ "%s",
+ p->can_user_rdpmc ? "enabled" : "disabled");
+ if (p->rdpmc_sysfs >= 0)
+ fprintf(fp, " (sysfs: %d)", p->rdpmc_sysfs);
+ if (p->can_user_rdpmc) {
+ fprintf(fp, ", ");
+ color_fprintf(fp,
+ p->rdpmc_works ?
+ PERF_COLOR_GREEN : PERF_COLOR_RED,
+ "%s",
+ p->rdpmc_works ?
+ "working" : "read failed");
+ }
+ if (p->pmc_width > 0)
+ fprintf(fp, " (width: %u bits)", p->pmc_width);
+ fputc('\n', fp);
+ }
+ }
+
+ fprintf(fp, " Max event group size: %s%d (active: %s%d)\n",
+ p->max_group_capped ? ">=" : "",
+ p->max_group_size,
+ p->max_active_capped ? ">=" : "",
+ p->max_active_group_size);
+ if (p->max_gp_group_size > 0 &&
+ (p->max_gp_group_size != p->max_group_size ||
+ p->max_active_gp_group_size != p->max_active_group_size)) {
+ fprintf(fp, " Max GP event group size: %s%d (active: %s%d)\n",
+ p->max_gp_group_capped ? ">=" : "",
+ p->max_gp_group_size,
+ p->max_active_gp_capped ? ">=" : "",
+ p->max_active_gp_group_size);
+ }
+ }
+ }
+}
+
+static int process_header_feature(const struct perf_tool *tool,
+ struct perf_session *session,
+ union perf_event *event)
+{
+ int ret = perf_event__process_feature(tool, session, event);
+
+ if (ret == 0 && event->header.size == sizeof(struct perf_record_header_feature) &&
+ (int)event->feat.feat_id >= session->header.last_feat) {
+ session_done = 1;
+ }
+ return ret;
+}
+
+static int process_sample_stop(const struct perf_tool *tool __maybe_unused,
+ union perf_event *event __maybe_unused,
+ struct perf_sample *sample __maybe_unused,
+ struct machine *machine __maybe_unused)
+{
+ session_done = 1;
+ return 0;
+}
+
+#define MAX_SUMMARY_METRICS 2048
+#define MAX_DRILLDOWN_LEVELS 16
+
+struct summary_metric_item {
+ char *pmu;
+ char *name;
+ char *groups;
+ int level;
+ bool has_children;
+ bool has_parent;
+};
+
+struct summary_metrics_state {
+ struct strlist *metrics;
+ struct strlist *groups;
+ struct summary_metric_item items[MAX_SUMMARY_METRICS];
+ size_t nr_items;
+};
+
+static bool group_list_has_token(const char *groups, const char *token)
+{
+ size_t tok_len;
+ const char *p;
+
+ if (!groups || !token || !*token)
+ return false;
+ tok_len = strlen(token);
+ p = groups;
+ while (*p) {
+ const char *semi = strchr(p, ';');
+ size_t len = semi ? (size_t)(semi - p) : strlen(p);
+
+ if (len == tok_len && !strncmp(p, token, len))
+ return true;
+ if (!semi)
+ break;
+ p = semi + 1;
+ }
+ return false;
+}
+
+static int collect_summary_metric_cb(const struct pmu_metric *pm,
+ const struct pmu_metrics_table *table __maybe_unused,
+ void *vdata)
+{
+ struct summary_metrics_state *st = vdata;
+
+ if (pm->metric_name)
+ strlist__add(st->metrics, pm->metric_name);
+
+ if (pm->metric_group) {
+ char *copy = strdup(pm->metric_group);
+ char *tok, *saveptr = NULL;
+
+ if (copy) {
+ for (tok = strtok_r(copy, ";", &saveptr); tok;
+ tok = strtok_r(NULL, ";", &saveptr)) {
+ if (*tok)
+ strlist__add(st->groups, tok);
+ }
+ free(copy);
+ }
+ }
+
+ if (pm->metric_name) {
+ const char *pmu_name = pm->pmu ?: "cpu";
+ struct summary_metric_item *existing = NULL;
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ if (st->items[i].pmu && st->items[i].name &&
+ !strcmp(st->items[i].pmu, pmu_name) &&
+ !strcmp(st->items[i].name, pm->metric_name)) {
+ existing = &st->items[i];
+ break;
+ }
+ }
+ if (!existing && st->nr_items < MAX_SUMMARY_METRICS) {
+ existing = &st->items[st->nr_items++];
+ existing->pmu = strdup(pmu_name);
+ existing->name = strdup(pm->metric_name);
+ existing->groups = strdup(pm->metric_group ?: "");
+ } else if (existing && pm->metric_group && existing->groups &&
+ !strstr(existing->groups, pm->metric_group)) {
+ char *merged = NULL;
+
+ if (asprintf(&merged, "%s;%s", existing->groups, pm->metric_group) > 0) {
+ free(existing->groups);
+ existing->groups = merged;
+ }
+ }
+ }
+ return 0;
+}
+
+static int compute_metric_drilldown(struct summary_metrics_state *st,
+ int level_counts[MAX_DRILLDOWN_LEVELS],
+ char *level_labels[MAX_DRILLDOWN_LEVELS])
+{
+ int max_level = 0;
+
+ memset(level_counts, 0, sizeof(int) * MAX_DRILLDOWN_LEVELS);
+ memset(level_labels, 0, sizeof(char *) * MAX_DRILLDOWN_LEVELS);
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ char child_grp[256];
+
+ if (!st->items[i].name || !st->items[i].pmu)
+ continue;
+ snprintf(child_grp, sizeof(child_grp), "%s_group", st->items[i].name);
+ if (!strlist__has_entry(st->groups, child_grp))
+ continue;
+
+ for (size_t j = 0; j < st->nr_items; j++) {
+ if (i == j || !st->items[j].groups || !st->items[j].pmu)
+ continue;
+ if (strcmp(st->items[i].pmu, st->items[j].pmu) != 0)
+ continue;
+ if (group_list_has_token(st->items[j].groups, child_grp)) {
+ st->items[i].has_children = true;
+ st->items[j].has_parent = true;
+ }
+ }
+ }
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ if (st->items[i].has_children && !st->items[i].has_parent) {
+ st->items[i].level = 1;
+ max_level = 1;
+ }
+ }
+
+ for (int d = 1; d < MAX_DRILLDOWN_LEVELS - 1; d++) {
+ bool progress = false;
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ char child_grp[256];
+
+ if (st->items[i].level != d || !st->items[i].has_children)
+ continue;
+ snprintf(child_grp, sizeof(child_grp), "%s_group", st->items[i].name);
+ for (size_t j = 0; j < st->nr_items; j++) {
+ if (i == j || !st->items[j].groups || !st->items[j].pmu)
+ continue;
+ if (strcmp(st->items[i].pmu, st->items[j].pmu) != 0)
+ continue;
+ if (group_list_has_token(st->items[j].groups, child_grp) &&
+ st->items[j].level < d + 1) {
+ st->items[j].level = d + 1;
+ if (d + 1 > max_level)
+ max_level = d + 1;
+ progress = true;
+ }
+ }
+ }
+ if (!progress)
+ break;
+ }
+
+ for (int d = 1; d <= max_level; d++) {
+ struct str_node *pos;
+ const char *best_label = NULL;
+ int best_hits = 0;
+ int total_at_d = 0;
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ if (st->items[i].level == d)
+ total_at_d++;
+ }
+ level_counts[d] = total_at_d;
+
+ strlist__for_each_entry(pos, st->groups) {
+ const char *g = pos->s;
+ size_t glen = strlen(g);
+ int hits_in_d = 0;
+ bool in_other_d = false;
+
+ if (!strcasecmp(g, "Default") || !strcasecmp(g, "Summary") ||
+ (glen > 6 && !strcmp(g + glen - 6, "_group")))
+ continue;
+
+ for (size_t i = 0; i < st->nr_items; i++) {
+ if (!st->items[i].groups || st->items[i].level == 0)
+ continue;
+ if (group_list_has_token(st->items[i].groups, g)) {
+ if (st->items[i].level == d)
+ hits_in_d++;
+ else
+ in_other_d = true;
+ }
+ }
+
+ if (!in_other_d &&
+ (hits_in_d > best_hits ||
+ (hits_in_d == best_hits && best_label &&
+ strlen(g) > strlen(best_label)))) {
+ best_hits = hits_in_d;
+ best_label = g;
+ }
+ }
+
+ if (best_label && best_hits * 2 >= total_at_d)
+ level_labels[d] = strdup(best_label);
+ }
+
+ return max_level;
+}
+
+static bool is_mem_bw_pmu_name(const char *name)
+{
+ if (!name)
+ return false;
+ return strstarts(name, "uncore_imc") ||
+ strstarts(name, "uncore_mc") ||
+ strstarts(name, "uncore_edc") ||
+ strstarts(name, "uncore_mchbm") ||
+ strstarts(name, "amd_df") ||
+ strstarts(name, "amd_umc") ||
+ strstarts(name, "arm_dmc") ||
+ strstarts(name, "dmc620") ||
+ strstarts(name, "arm_cmn") ||
+ strstr(name, "ddrc") != NULL ||
+ strstr(name, "ddr") != NULL ||
+ !strcmp(name, "hv_24x7") ||
+ strstarts(name, "nest_mc");
+}
+
+static bool is_io_bw_pmu_name(const char *name)
+{
+ if (!name)
+ return false;
+ return strstarts(name, "uncore_iio") ||
+ strstarts(name, "uncore_irp") ||
+ strstarts(name, "uncore_pcie") ||
+ strstarts(name, "uncore_upi") ||
+ strstarts(name, "uncore_qpi") ||
+ strstarts(name, "uncore_m2pcie") ||
+ strstarts(name, "uncore_m3upi") ||
+ strstarts(name, "uncore_arb") ||
+ strstarts(name, "cxl") ||
+ strstarts(name, "amd_iommu") ||
+ strstarts(name, "amd_xgmi") ||
+ strstarts(name, "arm_smmu") ||
+ strstr(name, "pcie") != NULL ||
+ strstarts(name, "dwc_rootport") ||
+ strstarts(name, "cci") ||
+ strstarts(name, "ccn");
+}
+
+static void print_strlist_color(FILE *fp, const char *color, struct strlist *list)
+{
+ struct str_node *pos;
+ bool first = true;
+
+ strlist__for_each_entry(pos, list) {
+ if (!first)
+ fprintf(fp, ", ");
+ color_fprintf(fp, color, "%s", pos->s);
+ first = false;
+ }
+}
+
+static void add_pmu_display_name(struct strlist *list, const struct perf_pmu *pmu)
+{
+ size_t num_inst = perf_pmu__num_duplicates(pmu);
+ char buf[128];
+
+ if (!pmu->name)
+ return;
+ if (num_inst > 1) {
+ size_t base_len = pmu_name_len_no_suffix(pmu->name);
+
+ snprintf(buf, sizeof(buf), "%.*s", (int)base_len, pmu->name);
+ strlist__add(list, buf);
+ } else {
+ strlist__add(list, pmu->name);
+ }
+}
+
+static void print_system_summary(FILE *fp, const struct perf_session *session,
+ bool probed, bool leading_newline)
+{
+ const struct pmu_metrics_table *mtable;
+ struct perf_pmu *pmu = NULL;
+ struct strlist *core_pmus = strlist__new(NULL, NULL);
+ struct strlist *mem_bw_pmus = strlist__new(NULL, NULL);
+ struct strlist *io_bw_pmus = strlist__new(NULL, NULL);
+ struct strlist *aux_pmus = strlist__new(NULL, NULL);
+ struct strlist *missing = strlist__new(NULL, NULL);
+ struct summary_metrics_state *mstate = zalloc(sizeof(*mstate));
+ int level_counts[MAX_DRILLDOWN_LEVELS];
+ char *level_labels[MAX_DRILLDOWN_LEVELS];
+ int max_drill_lvl = 0;
+ bool has_sw_sampling = false;
+ bool core_can_sample = false;
+ bool core_precise = false;
+ int max_precise = 0;
+ bool core_rdpmc = false;
+ bool core_branch_stack = false;
+ int max_br_depth = 0;
+ bool core_mem_events = false;
+ bool core_leader_sampling = false;
+ size_t total_pmus = 0, total_events = 0, total_sysfs_events = 0, total_json_events = 0;
+ size_t nr_core, nr_metrics, nr_groups;
+
+ if (!mstate)
+ goto out_free;
+ mstate->metrics = strlist__new(NULL, NULL);
+ mstate->groups = strlist__new(NULL, NULL);
+
+ if (!core_pmus || !mem_bw_pmus || !io_bw_pmus || !aux_pmus ||
+ !missing || !mstate->metrics || !mstate->groups)
+ goto out_free;
+
+ while ((pmu = perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
+ size_t pmu_events = perf_pmu__num_events(pmu);
+ size_t sysfs_ev = pmu->sysfs_aliases;
+ size_t json_ev = pmu_events > sysfs_ev ? pmu_events - sysfs_ev : 0;
+
+ total_pmus++;
+ total_events += pmu_events;
+ total_sysfs_events += sysfs_ev;
+ total_json_events += json_ev;
+
+ if (pmu->is_core) {
+ struct perf_pmu_caps *br_cap;
+
+ add_pmu_display_name(core_pmus, pmu);
+ perf_pmu__caps_parse(pmu);
+ br_cap = perf_pmu__get_cap(pmu, "branches");
+ if (br_cap && br_cap->value) {
+ int depth = atoi(br_cap->value);
+
+ if (depth > max_br_depth)
+ max_br_depth = depth;
+ }
+ if (probed && pmu->probed.checked && pmu->probed.open_supported) {
+ if (pmu->probed.can_sample)
+ core_can_sample = true;
+ if (pmu->probed.max_precise > 0) {
+ core_precise = true;
+ if (pmu->probed.max_precise > max_precise)
+ max_precise = pmu->probed.max_precise;
+ }
+ if (pmu->probed.can_user_rdpmc)
+ core_rdpmc = true;
+ if (pmu->probed.can_branch_stack)
+ core_branch_stack = true;
+ if (pmu->probed.mem_events_mask)
+ core_mem_events = true;
+ if (pmu->probed.can_leader_sampling)
+ core_leader_sampling = true;
+ } else {
+ core_can_sample = true;
+ if (pmu->max_precise > 0) {
+ core_precise = true;
+ if (pmu->max_precise > max_precise)
+ max_precise = pmu->max_precise;
+ }
+ if (max_br_depth > 0)
+ core_branch_stack = true;
+ if (pmu->mem_events)
+ core_mem_events = true;
+ }
+ } else if (pmu->type == PERF_TYPE_SOFTWARE) {
+ if (!probed || !pmu->probed.checked || pmu->probed.can_sample)
+ has_sw_sampling = true;
+ }
+
+ if (pmu->auxtrace)
+ add_pmu_display_name(aux_pmus, pmu);
+ if (is_mem_bw_pmu_name(pmu->name))
+ add_pmu_display_name(mem_bw_pmus, pmu);
+ if (is_io_bw_pmu_name(pmu->name))
+ add_pmu_display_name(io_bw_pmus, pmu);
+ }
+
+ if (session && session->header.env.arch && session->header.env.cpuid)
+ mtable = find_core_metrics_table(session->header.env.arch,
+ session->header.env.cpuid);
+ else
+ mtable = pmu_metrics_table__find();
+
+ metricgroup__for_each_metric(mtable, collect_summary_metric_cb, mstate);
+ max_drill_lvl = compute_metric_drilldown(mstate, level_counts, level_labels);
+
+ nr_core = strlist__nr_entries(core_pmus);
+ nr_metrics = strlist__nr_entries(mstate->metrics);
+ nr_groups = strlist__nr_entries(mstate->groups);
+
+ if (leading_newline)
+ fputc('\n', fp);
+ color_fprintf(fp, PERF_COLOR_BOLD, "Summary:");
+ fputc('\n', fp);
+ if (nr_core == 0) {
+ const char *sw_desc = has_sw_sampling ?
+ "minimal system; sampling only via software timer events" :
+ "no sampling support detected";
+
+ color_fprintf(fp, PERF_COLOR_BOLD, " Core PMUs:");
+ fprintf(fp, " ");
+ color_fprintf(fp, PERF_COLOR_RED, "none");
+ fprintf(fp, " (%s)\n", sw_desc);
+ strlist__add(missing, "hardware core PMU");
+ } else {
+ color_fprintf(fp, PERF_COLOR_BOLD, " Core PMUs (%zu%s):", nr_core,
+ nr_core > 1 ? ", hybrid" : "");
+ fprintf(fp, " ");
+ print_strlist_color(fp, PERF_COLOR_GREEN, core_pmus);
+ fputc('\n', fp);
+
+ color_fprintf(fp, PERF_COLOR_BOLD, " Core features:");
+ fputc('\n', fp);
+ fprintf(fp, " Interrupt-based sampling: ");
+ color_fprintf(fp, core_can_sample ? PERF_COLOR_GREEN : PERF_COLOR_RED,
+ "%s", core_can_sample ? "supported" : "missing");
+ fputc('\n', fp);
+ if (!core_can_sample)
+ strlist__add(missing, "core interrupt sampling");
+
+ fprintf(fp, " Precise event sampling: ");
+ if (core_precise) {
+ color_fprintf(fp, PERF_COLOR_GREEN, "supported");
+ fprintf(fp, " (max_precise: %d [%s])\n",
+ max_precise, precise_level_desc(max_precise));
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "missing");
+ fprintf(fp, " (%s)\n", precise_level_desc(0));
+ strlist__add(missing, "precise event sampling (PEBS/IBS/SPE)");
+ }
+
+ fprintf(fp, " Branch stack sampling (LBR/BRBE): ");
+ if (core_branch_stack) {
+ color_fprintf(fp, PERF_COLOR_GREEN, "supported");
+ if (max_br_depth > 0)
+ fprintf(fp, " (depth: %d branches)\n", max_br_depth);
+ else
+ fputc('\n', fp);
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "missing");
+ fputc('\n', fp);
+ strlist__add(missing, "hardware branch stack sampling (LBR/BRBE)");
+ }
+
+ if (probed) {
+ fprintf(fp, " User-space counter reading (rdpmc): ");
+ color_fprintf(fp, core_rdpmc ? PERF_COLOR_GREEN : PERF_COLOR_YELLOW,
+ "%s", core_rdpmc ? "supported" : "missing/disabled");
+ fputc('\n', fp);
+ if (!core_rdpmc)
+ strlist__add(missing, "user-space counter reading (rdpmc)");
+
+ fprintf(fp, " Leader sampling: ");
+ color_fprintf(fp,
+ core_leader_sampling ? PERF_COLOR_GREEN : PERF_COLOR_RED,
+ "%s",
+ core_leader_sampling ? "supported" : "missing");
+ fputc('\n', fp);
+ }
+
+ fprintf(fp, " Memory profiling events (DATA_SRC): ");
+ color_fprintf(fp, core_mem_events ? PERF_COLOR_GREEN : PERF_COLOR_RED,
+ "%s", core_mem_events ? "supported" : "missing");
+ fputc('\n', fp);
+ if (!core_mem_events)
+ strlist__add(missing, "memory load/store profiling events");
+
+ fprintf(fp, " Hardware AUX trace PMUs: ");
+ if (!strlist__empty(aux_pmus)) {
+ print_strlist_color(fp, PERF_COLOR_GREEN, aux_pmus);
+ fputc('\n', fp);
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "missing");
+ fputc('\n', fp);
+ strlist__add(missing, "hardware AUX trace PMU");
+ }
+ }
+
+ color_fprintf(fp, PERF_COLOR_BOLD, " Bus & uncore monitoring:");
+ fputc('\n', fp);
+ fprintf(fp, " Memory bandwidth PMUs: ");
+ if (!strlist__empty(mem_bw_pmus)) {
+ print_strlist_color(fp, PERF_COLOR_GREEN, mem_bw_pmus);
+ fputc('\n', fp);
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "missing");
+ fputc('\n', fp);
+ strlist__add(missing, "memory bus bandwidth PMUs");
+ }
+
+ fprintf(fp, " PCIe / IO interconnect bandwidth PMUs: ");
+ if (!strlist__empty(io_bw_pmus)) {
+ print_strlist_color(fp, PERF_COLOR_GREEN, io_bw_pmus);
+ fputc('\n', fp);
+ } else {
+ color_fprintf(fp, PERF_COLOR_RED, "missing");
+ fputc('\n', fp);
+ strlist__add(missing, "PCIe/IO interconnect bandwidth PMUs");
+ }
+
+ color_fprintf(fp, PERF_COLOR_BOLD, " Events & metrics:");
+ fputc('\n', fp);
+ fprintf(fp, " Available events: %zu total (%zu sysfs, %zu json) across %zu PMUs\n",
+ total_events, total_sysfs_events, total_json_events, total_pmus);
+ if (nr_metrics == 0) {
+ fprintf(fp, " Available metrics: ");
+ color_fprintf(fp, PERF_COLOR_RED, "none");
+ fprintf(fp, " (missing JSON metrics)\n");
+ strlist__add(missing, "multi-level pipeline drill-down and JSON metrics");
+ } else {
+ const char *tier = (max_drill_lvl >= 2) ? "advanced" : "minimal";
+ const char *tier_col = (max_drill_lvl >= 2) ?
+ PERF_COLOR_GREEN : PERF_COLOR_YELLOW;
+
+ fprintf(fp, " Available metrics: %zu metrics in %zu groups (",
+ nr_metrics, nr_groups);
+ color_fprintf(fp, tier_col, "%s", tier);
+ fprintf(fp, ")\n");
+ if (max_drill_lvl > 0) {
+ fprintf(fp, " Metric drill-down levels (%d): ", max_drill_lvl);
+ for (int d = 1; d <= max_drill_lvl; d++) {
+ if (d > 1)
+ fprintf(fp, ", ");
+ color_fprintf(fp, PERF_COLOR_CYAN, "L%d", d);
+ if (level_labels[d])
+ fprintf(fp, " (%s: %d metrics)",
+ level_labels[d], level_counts[d]);
+ else
+ fprintf(fp, " (%d metrics)", level_counts[d]);
+ }
+ fputc('\n', fp);
+ } else {
+ fprintf(fp, " Metric drill-down levels: ");
+ color_fprintf(fp, PERF_COLOR_YELLOW, "none");
+ fprintf(fp, " (flat metrics only)\n");
+ }
+ if (max_drill_lvl < 2) {
+ strlist__add(missing,
+ "multi-level pipeline drill-down metrics (<metric>_group)");
+ }
+ }
+
+ color_fprintf(fp, PERF_COLOR_BOLD, " System rating:");
+ if (nr_core == 0) {
+ const char *min_desc =
+ "no hardware core PMU; profiling limited to software timer events";
+
+ fprintf(fp, " ");
+ color_fprintf(fp, PERF_COLOR_RED, "Minimal");
+ fprintf(fp, " (%s)\n", min_desc);
+ } else if (core_precise && core_branch_stack && (!probed || core_rdpmc) &&
+ !strlist__empty(mem_bw_pmus) && max_drill_lvl >= 2) {
+ const char *core_adv = "precise sampling, branch stack (LBR), user rdpmc";
+ const char *sys_adv = "bus PMUs, and metric drill-down";
+
+ fprintf(fp, " ");
+ color_fprintf(fp, PERF_COLOR_GREEN, "Advanced");
+ fprintf(fp, " (core PMU with %s, %s)\n", core_adv, sys_adv);
+ } else if (core_can_sample &&
+ (core_precise || core_branch_stack || max_drill_lvl >= 1)) {
+ const char *std_desc =
+ "core PMU with hardware sampling and partial advanced features or metrics";
+
+ fprintf(fp, " ");
+ color_fprintf(fp, PERF_COLOR_CYAN, "Standard");
+ fprintf(fp, " (%s)\n", std_desc);
+ } else {
+ const char *bas_desc =
+ "core PMU with basic counting/sampling only; missing advanced features";
+
+ fprintf(fp, " ");
+ color_fprintf(fp, PERF_COLOR_YELLOW, "Basic");
+ fprintf(fp, " (%s)\n", bas_desc);
+ }
+
+ if (!strlist__empty(missing)) {
+ color_fprintf(fp, PERF_COLOR_BOLD, " Missing baseline features:");
+ fprintf(fp, " ");
+ print_strlist_color(fp, PERF_COLOR_RED, missing);
+ fputc('\n', fp);
+ }
+
+ for (int d = 1; d <= max_drill_lvl; d++)
+ free(level_labels[d]);
+
+out_free:
+ strlist__delete(core_pmus);
+ strlist__delete(mem_bw_pmus);
+ strlist__delete(io_bw_pmus);
+ strlist__delete(aux_pmus);
+ strlist__delete(missing);
+ if (mstate) {
+ for (size_t i = 0; i < mstate->nr_items; i++) {
+ free(mstate->items[i].pmu);
+ free(mstate->items[i].name);
+ free(mstate->items[i].groups);
+ }
+ strlist__delete(mstate->metrics);
+ strlist__delete(mstate->groups);
+ free(mstate);
+ }
+}
+
+int cmd_sysinfo(int argc, const char **argv)
+{
+ bool json = false;
+ bool show_pmus = false;
+ bool show_all = false;
+ bool force = false;
+ bool do_probe = true;
+ const char *output_path = NULL;
+ const char *input_name = NULL;
+ FILE *fp = stdout;
+ struct perf_data data = {
+ .mode = PERF_DATA_MODE_READ,
+ };
+ struct perf_tool tool;
+ struct perf_session *session = NULL;
+ struct perf_pmu *pmu = NULL;
+ size_t pmu_idx = 0;
+ int ret = 0;
+ const struct option sysinfo_options[] = {
+ OPT_STRING('i', "input", &input_name, "file",
+ "Input perf.data file name to read PMUs from"),
+ OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
+ OPT_STRING('o', "output", &output_path, "file", "output file name"),
+ OPT_BOOLEAN('p', "pmus", &show_pmus,
+ "Display detailed information for each PMU"),
+ OPT_BOOLEAN('j', "json", &json, "JSON encode PMU information"),
+ OPT_BOOLEAN('v', "verbose", &show_all,
+ "Show all similar PMUs with alphanumeric suffixes"),
+ OPT_BOOLEAN('a', "all", &show_all,
+ "Show all similar PMUs with alphanumeric suffixes"),
+ OPT_BOOLEAN(0, "probe", &do_probe,
+ "Probe PMU capabilities on live system (default: on)"),
+ OPT_INCR(0, "debug", &verbose, "Enable debugging output"),
+ OPT_END()
+ };
+ const char * const sysinfo_usage[] = {
+ "perf sysinfo [<options>] [pmu_glob ...]",
+ NULL
+ };
+
+ argc = parse_options(argc, argv, sysinfo_options, sysinfo_usage,
+ PARSE_OPT_STOP_AT_NON_OPTION);
+
+ if (show_all || json || argc > 0)
+ show_pmus = true;
+
+ if (output_path) {
+ perf_use_color_default = 0;
+ fp = fopen(output_path, "w");
+ if (!fp) {
+ pr_err("Failed to open output file '%s': %m\n", output_path);
+ return -1;
+ }
+ } else {
+ setup_pager();
+ }
+
+ if (input_name) {
+ data.path = input_name;
+ data.force = force;
+
+ perf_tool__init(&tool, /*ordered_events=*/false);
+ tool.attr = perf_event__process_attr;
+ tool.feature = process_header_feature;
+ tool.sample = process_sample_stop;
+
+ session = perf_session__new(&data, &tool);
+ if (IS_ERR(session)) {
+ ret = PTR_ERR(session);
+ pr_err("Error opening %s: %s\n", input_name, strerror(-ret));
+ goto out_close;
+ }
+
+ if (data.is_pipe)
+ perf_session__process_events(session);
+
+ ret = perf_pmus__read_from_env(&session->header.env);
+ if (ret) {
+ pr_err("Failed to read PMU information from %s: %s\n",
+ input_name, strerror(-ret));
+ goto out_session;
+ }
+ }
+
+ if (json)
+ fputs("[", fp);
+
+ while ((pmu = show_all ? perf_pmus__scan(pmu) :
+ perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
+ if (!pmu_matches_filters(pmu, argc, argv))
+ continue;
+
+ if (do_probe && !input_name &&
+ (show_pmus || pmu->is_core || pmu->type == PERF_TYPE_SOFTWARE))
+ perf_pmu__probe(pmu);
+
+ if (!show_pmus)
+ continue;
+
+ if (json) {
+ if (pmu_idx > 0)
+ fputs(",\n", fp);
+ else
+ fputs("\n", fp);
+ print_pmu_json(fp, pmu, session, show_all);
+ } else {
+ if (pmu_idx > 0)
+ fputc('\n', fp);
+ print_pmu_text(fp, pmu, session, show_all);
+ }
+ pmu_idx++;
+ }
+
+ if (json)
+ fputs(pmu_idx > 0 ? "\n]\n" : "]\n", fp);
+ else if (argc == 0)
+ print_system_summary(fp, session, do_probe && !input_name,
+ pmu_idx > 0);
+
+out_session:
+ if (session)
+ perf_session__delete(session);
+out_close:
+ if (output_path && fp)
+ fclose(fp);
+ return ret;
+}
diff --git a/tools/perf/builtin.h b/tools/perf/builtin.h
index e0b430821abc..28e85c054468 100644
--- a/tools/perf/builtin.h
+++ b/tools/perf/builtin.h
@@ -37,6 +37,7 @@ int cmd_list(int argc, const char **argv);
int cmd_record(int argc, const char **argv);
int cmd_report(int argc, const char **argv);
int cmd_stat(int argc, const char **argv);
+int cmd_sysinfo(int argc, const char **argv);
int cmd_timechart(int argc, const char **argv);
int cmd_top(int argc, const char **argv);
int cmd_script(int argc, const char **argv);
diff --git a/tools/perf/perf.c b/tools/perf/perf.c
index d60bc929c257..a6fab1e6eb1c 100644
--- a/tools/perf/perf.c
+++ b/tools/perf/perf.c
@@ -112,6 +112,7 @@ static const struct cmd_struct commands[] = {
{ "report", cmd_report, 0 },
{ "bench", cmd_bench, 0 },
{ "stat", cmd_stat, 0 },
+ { "sysinfo", cmd_sysinfo, 0 },
{ "timechart", cmd_timechart, 0 },
{ "top", cmd_top, 0 },
{ "annotate", cmd_annotate, 0 },
diff --git a/tools/perf/tests/shell/sysinfo.sh b/tools/perf/tests/shell/sysinfo.sh
new file mode 100755
index 000000000000..40e90af6dca2
--- /dev/null
+++ b/tools/perf/tests/shell/sysinfo.sh
@@ -0,0 +1,71 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# perf sysinfo tests
+
+set -e
+
+shelldir=$(dirname "$0")
+. "${shelldir}"/lib/setup_python.sh
+
+sysinfo_output=$(mktemp /tmp/__perf_test.sysinfo_output.XXXXX)
+perf_data=$(mktemp /tmp/__perf_test.sysinfo.perf.data.XXXXX)
+
+cleanup() {
+ rm -f "${sysinfo_output}" "${perf_data}" "${perf_data}.old"
+ trap - EXIT TERM INT
+}
+
+trap_cleanup() {
+ cleanup
+ exit 1
+}
+trap trap_cleanup EXIT TERM INT
+
+test_sysinfo_default() {
+ echo "Default perf sysinfo output test"
+ perf sysinfo -o "${sysinfo_output}"
+ grep -q "^Summary:" "${sysinfo_output}"
+ grep -q "System rating:" "${sysinfo_output}"
+ perf sysinfo --pmus -o "${sysinfo_output}"
+ grep -q "^software (" "${sysinfo_output}"
+ grep -q "^Summary:" "${sysinfo_output}"
+ echo "Default perf sysinfo output test [Success]"
+}
+
+test_sysinfo_json() {
+ echo "Json perf sysinfo output test"
+ perf sysinfo -j -o "${sysinfo_output}"
+ $PYTHON -m json.tool "${sysinfo_output}" /dev/null
+ echo "Json perf sysinfo output test [Success]"
+}
+
+test_sysinfo_filter() {
+ echo "Filtered perf sysinfo output test"
+ perf sysinfo -o "${sysinfo_output}" software
+ grep -q "^software (" "${sysinfo_output}"
+ grep -q "Sample types:.*ip" "${sysinfo_output}"
+ grep -q "User registers:" "${sysinfo_output}"
+ grep -q "Intr registers:" "${sysinfo_output}"
+ grep -q "Features:.*leader_sampling" "${sysinfo_output}"
+ grep -q "Features:.*sw_grouping" "${sysinfo_output}"
+ echo "Filtered perf sysinfo output test [Success]"
+}
+
+test_sysinfo_perf_data() {
+ echo "perf.data perf sysinfo test"
+ perf record -e software/cpu-clock/u -o "${perf_data}" -- true 2>/dev/null
+ perf sysinfo -i "${perf_data}" -o "${sysinfo_output}"
+ grep -q "^Summary:" "${sysinfo_output}"
+ perf sysinfo --pmus -i "${perf_data}" -o "${sysinfo_output}"
+ grep -q "software" "${sysinfo_output}"
+ perf sysinfo -i "${perf_data}" -j -o "${sysinfo_output}"
+ $PYTHON -m json.tool "${sysinfo_output}" /dev/null
+ echo "perf.data perf sysinfo test [Success]"
+}
+
+test_sysinfo_default
+test_sysinfo_json
+test_sysinfo_filter
+test_sysinfo_perf_data
+cleanup
+exit 0
--
2.56.0.212.g129ede20d9-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test
2026-10-16 21:32 ` [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test Ian Rogers
@ 2026-10-16 21:45 ` sashiko-bot
0 siblings, 0 replies; 5+ messages in thread
From: sashiko-bot @ 2026-10-16 21:45 UTC (permalink / raw)
To: Ian Rogers; +Cc: linux-perf-users
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] perf sysinfo: broken perf.data metrics lookup in print_system_summary()
- [Medium] perf sysinfo: inaccurate mem_events detection in print_system_summary()
--
commit eeafacdf44b45876a713b51b3eacc1d62e8dae1a
Author: Ian Rogers <irogers@google.com>
perf sysinfo: Add sysinfo subcommand, documentation, and test
This commit adds the perf sysinfo subcommand to display and probe PMU and
system performance monitoring capabilities on a live system or from a
perf.data file.
> diff --git a/tools/perf/builtin-sysinfo.c b/tools/perf/builtin-sysinfo.c
> new file mode 100644
> index 0000000000000..8bc13f3dedb0b
> --- /dev/null
> +++ b/tools/perf/builtin-sysinfo.c
> @@ -0,0 +1,1958 @@
[ ... ]
> +static void print_system_summary(FILE *fp, const struct perf_session *session,
> + bool probed, bool leading_newline)
> +{
> + const struct pmu_metrics_table *mtable;
[ ... ]
> + while ((pmu = perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
> + size_t pmu_events = perf_pmu__num_events(pmu);
> + size_t sysfs_ev = pmu->sysfs_aliases;
> + size_t json_ev = pmu_events > sysfs_ev ? pmu_events - sysfs_ev : 0;
> +
> + total_pmus++;
> + total_events += pmu_events;
> + total_sysfs_events += sysfs_ev;
> + total_json_events += json_ev;
> +
> + if (pmu->is_core) {
> + struct perf_pmu_caps *br_cap;
> +
> + add_pmu_display_name(core_pmus, pmu);
> + perf_pmu__caps_parse(pmu);
> + br_cap = perf_pmu__get_cap(pmu, "branches");
> + if (br_cap && br_cap->value) {
> + int depth = atoi(br_cap->value);
> +
> + if (depth > max_br_depth)
> + max_br_depth = depth;
> + }
> + if (probed && pmu->probed.checked && pmu->probed.open_supported) {
> + if (pmu->probed.can_sample)
> + core_can_sample = true;
> + if (pmu->probed.max_precise > 0) {
> + core_precise = true;
> + if (pmu->probed.max_precise > max_precise)
> + max_precise = pmu->probed.max_precise;
> + }
> + if (pmu->probed.can_user_rdpmc)
> + core_rdpmc = true;
> + if (pmu->probed.can_branch_stack)
> + core_branch_stack = true;
> + if (pmu->probed.mem_events_mask)
> + core_mem_events = true;
> + if (pmu->probed.can_leader_sampling)
> + core_leader_sampling = true;
> + } else {
> + core_can_sample = true;
> + if (pmu->max_precise > 0) {
> + core_precise = true;
> + if (pmu->max_precise > max_precise)
> + max_precise = pmu->max_precise;
> + }
> + if (max_br_depth > 0)
> + core_branch_stack = true;
> + if (pmu->mem_events)
> + core_mem_events = true;
> + }
[Severity: Medium]
Can this misreport core_mem_events in print_system_summary()?
On AMD x86 and ARM64 systems, pmu->mem_events is attached to non-core PMUs
(ibs_op and arm_spe_*, where pmu->is_core is false), while the core PMU has
pmu->mem_events == NULL. Checking mem_events only inside the if (pmu->is_core)
block causes the summary to always report memory profiling events as missing
on those architectures.
Conversely, in the unprobed else branch, checking if (pmu->mem_events)
without calling perf_pmu__mem_events_init_pmu(pmu) (unlike
print_mem_events_static()) will set core_mem_events = true whenever
perf_pmu__arch_init() assigns a static perf_mem_events array to a core PMU,
even if none of the events (such as events/mem-loads or events/mem-stores)
are actually supported in sysfs.
> + } else if (pmu->type == PERF_TYPE_SOFTWARE) {
> + if (!probed || !pmu->probed.checked || pmu->probed.can_sample)
> + has_sw_sampling = true;
> + }
> +
> + if (pmu->auxtrace)
> + add_pmu_display_name(aux_pmus, pmu);
> + if (is_mem_bw_pmu_name(pmu->name))
> + add_pmu_display_name(mem_bw_pmus, pmu);
> + if (is_io_bw_pmu_name(pmu->name))
> + add_pmu_display_name(io_bw_pmus, pmu);
> + }
> +
> + if (session && session->header.env.arch && session->header.env.cpuid)
> + mtable = find_core_metrics_table(session->header.env.arch,
> + session->header.env.cpuid);
> + else
> + mtable = pmu_metrics_table__find();
[Severity: Medium]
Will find_core_metrics_table() fail to match the metrics table when reading
from a perf.data file here?
session->header.env.arch contains the raw uts.machine string from
HEADER_ARCH (such as "x86_64", "aarch64", or "ppc64le"), whereas
pmu_events_map[].arch uses the normalized architecture name returned by
perf_env__arch(&session->header.env) ("x86", "arm64", "powerpc", etc.).
In addition, on x86, session->header.env.cpuid stores "vendor,family,model,step"
in decimal, whereas pmu_events_map and strcmp_cpuid_str() expect the
"vendor-family-HEXMODEL-HEXSTEP" format. In perf_pmus__read_from_env() in
tools/perf/util/pmus.c, both conversions are performed before calling
find_core_events_table():
if (env->cpuid) {
char cpuid_str[128];
char vendor[32];
unsigned int family, model, step;
const char *cpuid = env->cpuid;
if (sscanf(env->cpuid, "%31[^,],%u,%u,%u",
vendor, &family, &model, &step) == 4) {
snprintf(cpuid_str, sizeof(cpuid_str), "%s-%u-%X-%X",
vendor, family, model, step);
cpuid = cpuid_str;
}
core_table = find_core_events_table(perf_env__arch(env), cpuid);
}
Also, if session is non-NULL (-i perf.data) but either arch or cpuid is NULL
in the header, falling into the else branch calls pmu_metrics_table__find(),
which queries the live host CPU's metrics table instead of treating the
recorded environment as having no core metrics table.
[ ... ]
> + while ((pmu = show_all ? perf_pmus__scan(pmu) :
> + perf_pmus__scan_skip_duplicates(pmu)) != NULL) {
> + if (!pmu_matches_filters(pmu, argc, argv))
> + continue;
> +
> + if (do_probe && !input_name &&
> + (show_pmus || pmu->is_core || pmu->type == PERF_TYPE_SOFTWARE))
> + perf_pmu__probe(pmu);
[Severity: Medium]
Related to the core_mem_events check in print_system_summary(), when
show_pmus is false, should this condition also probe PMUs that have
pmu->mem_events != NULL so that non-core memory profiling PMUs (such as
ibs_op and arm_spe_*) are probed for the default summary output?
[ ... ]
> +}
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261016213258.945737-1-irogers@google.com?part=2
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing
2026-10-16 21:32 ` [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing Ian Rogers
@ 2026-10-16 21:56 ` sashiko-bot
0 siblings, 0 replies; 5+ messages in thread
From: sashiko-bot @ 2026-10-16 21:56 UTC (permalink / raw)
To: Ian Rogers; +Cc: linux-perf-users
Thank you for your contribution! Sashiko AI review found 6 potential issue(s) to consider:
- [High] perf pmus: out-of-bounds container_of() access in env_pmu_find_or_add()
- [Medium] perf pmus: broken CPUID matching in perf_pmus__read_from_env()
- [Medium] perf pmu: broken bulk and callchain probing in probe_sample_types()
- [Medium] perf pmu: fixed-counter ref-cycles in GP probe in perf_pmu__probe()
- [Medium] perf pmu: duplicate legacy XMM and SIMD probing in probe_pmu_regs_one()
- [Medium] perf pmu: unchecked CPU_SET() index in probe_group_limits()
--
commit 73f853dff74bd3f7177753b6ce1c952979dbfcbb
Author: Ian Rogers <irogers@google.com>
perf pmus: Add PMU environment loading and live capability probing
This commit adds helpers to reconstruct PMU lists and capabilities from
perf_env headers, exposes duplicate uncore PMU scanning and mem-events
formatting helpers, and adds perf_pmu__probe() to probe live PMU
capabilities via perf_event_open().
> diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c
> index 01753d5c69d13..0d1c5ba7d426d 100644
> --- a/tools/perf/util/pmu.c
> +++ b/tools/perf/util/pmu.c
[ ... ]
> @@ -2798,9 +2844,1935 @@ void perf_pmu__delete(struct perf_pmu *pmu)
[ ... ]
> +static void probe_group_limits(const struct perf_event_attr *attrs, size_t nr_attrs,
> + pid_t pid, int cpu, unsigned long flags,
> + int *max_open, bool *open_capped,
> + int *max_active, bool *active_capped)
> +{
> + struct perf_event_attr leader_attr;
> + int leader_fd;
> + int fds[MAX_PROBE_GROUP_SIZE];
> + int nr_followers = 0;
> + bool has_time_read = true;
> + bool active_ok = true;
> + enum rlimit_action set_rlimit = NO_CHANGE;
> + cpu_set_t saved_affinity, probe_affinity;
> + bool affinity_changed = false;
> +
> + *max_open = 0;
> + *open_capped = false;
> + *max_active = 0;
> + *active_capped = false;
> +
> + if (!attrs || nr_attrs == 0)
> + return;
> +
> + if (pid == 0 && cpu >= 0) {
> + CPU_ZERO(&saved_affinity);
> + if (sched_getaffinity(0, sizeof(saved_affinity), &saved_affinity) == 0) {
> + CPU_ZERO(&probe_affinity);
> + CPU_SET(cpu, &probe_affinity);
[Severity: Medium]
Can CPU_SET(cpu, &probe_affinity) write out of bounds on the stack here when
cpu >= CPU_SETSIZE?
In perf_pmu__probe() -> probe_group_limits(), cpu comes from
select_probe_cpu(pmu), which returns the first online CPU in pmu->cpus
without bounding it to CPU_SETSIZE.
Unlike probe_mmap_caps() and probe_pmu_skid() later in this file, which both
check pmu_cpu < CPU_SETSIZE before calling CPU_SET(), probe_group_limits()
only checks cpu >= 0. On systems with CPU IDs >= 1024, this can write past
probe_affinity on libcs without bounds checking (such as musl) or produce an
empty affinity mask on glibc.
> + if (sched_setaffinity(0, sizeof(probe_affinity), &probe_affinity) == 0)
> + affinity_changed = true;
> + }
> + }
[ ... ]
> +static void probe_sample_types(struct perf_pmu *pmu,
> + const struct perf_event_attr *base_attr,
> + pid_t pid, int cpu, unsigned long flags)
> +{
> + u64 reg_bit = BIT_ULL(perf_arch_reg_ip(EM_HOST)) ?: 1ULL;
> + u64 bulk_mask = PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_TIME |
> + PERF_SAMPLE_ADDR | PERF_SAMPLE_READ | PERF_SAMPLE_CALLCHAIN |
> + PERF_SAMPLE_ID | PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD |
> + PERF_SAMPLE_STREAM_ID | PERF_SAMPLE_RAW | PERF_SAMPLE_REGS_USER |
> + PERF_SAMPLE_STACK_USER | PERF_SAMPLE_WEIGHT | PERF_SAMPLE_DATA_SRC |
> + PERF_SAMPLE_IDENTIFIER | PERF_SAMPLE_TRANSACTION |
> + PERF_SAMPLE_REGS_INTR | PERF_SAMPLE_AUX | PERF_SAMPLE_CGROUP |
> + PERF_SAMPLE_DATA_PAGE_SIZE | PERF_SAMPLE_CODE_PAGE_SIZE |
> + PERF_SAMPLE_WEIGHT_STRUCT;
> + struct perf_event_attr b_attr = *base_attr;
> + int b_fd;
> +
> + b_attr.disabled = 1;
> + b_attr.sample_period = base_attr->sample_period ?: 10000;
> + b_attr.sample_type = bulk_mask;
> + b_attr.sample_regs_user = reg_bit;
> + b_attr.sample_regs_intr = reg_bit;
> + b_attr.sample_stack_user = 64;
> + b_attr.inherit = 0;
> + b_fd = sys_perf_event_open(&b_attr, pid, cpu, -1, flags);
> + if (b_fd >= 0) {
> + close(b_fd);
> + pmu->probed.sample_types |= bulk_mask;
> + }
> +
> + for (unsigned int shift = 0; (1ULL << shift) < PERF_SAMPLE_MAX; shift++) {
> + u64 bit = 1ULL << shift;
> + struct perf_event_attr attr = *base_attr;
> + int fd;
> +
> + if (pmu->probed.sample_types & bit)
> + continue;
> +
> + attr.disabled = 1;
> + attr.sample_period = base_attr->sample_period ?: 10000;
> + attr.sample_type = bit;
> +
> + switch (bit) {
> + case PERF_SAMPLE_BRANCH_STACK:
> + attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY |
> + (attr.exclude_kernel ? PERF_SAMPLE_BRANCH_USER : 0);
> + break;
> + case PERF_SAMPLE_REGS_USER:
> + attr.sample_regs_user = reg_bit;
> + break;
> + case PERF_SAMPLE_REGS_INTR:
> + attr.sample_regs_intr = reg_bit;
> + break;
> + case PERF_SAMPLE_STACK_USER:
> + attr.sample_stack_user = 64;
> + break;
> + case PERF_SAMPLE_READ:
> + attr.inherit = 0;
> + break;
> + default:
> + break;
> + }
> +
> + fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
[Severity: Medium]
There appear to be two issues in probe_sample_types():
First, bulk_mask sets both PERF_SAMPLE_WEIGHT and PERF_SAMPLE_WEIGHT_STRUCT
(as well as PERF_SAMPLE_AUX without an AUX group leader). In
kernel/events/core.c:perf_copy_attr():
if ((attr->sample_type & PERF_SAMPLE_WEIGHT) &&
(attr->sample_type & PERF_SAMPLE_WEIGHT_STRUCT))
return -EINVAL;
Doesn't this cause the bulk sys_perf_event_open(&b_attr, ...) fast-path to
always fail with -EINVAL?
Second, in the per-bit fallback loop, when base_attr->exclude_kernel == 1
(for example, when running unprivileged with perf_event_paranoid >= 1),
probing PERF_SAMPLE_CALLCHAIN leaves attr.exclude_callchain_kernel == 0. In
kernel/events/core.c:SYSCALL_DEFINE5(perf_event_open):
if (!attr.exclude_kernel ||
((attr.sample_type & PERF_SAMPLE_CALLCHAIN) &&
!attr.exclude_callchain_kernel)) {
err = perf_allow_kernel();
if (err)
return err;
}
When perf_allow_kernel() denies kernel profiling, won't the kernel reject
PERF_SAMPLE_CALLCHAIN with -EACCES and cause pmu->probed.can_callchain to be
falsely reported as false unless attr.exclude_callchain_kernel =
attr.exclude_kernel is set?
> + if (fd < 0 && bit == PERF_SAMPLE_BRANCH_STACK) {
> + attr.branch_sample_type = PERF_SAMPLE_BRANCH_ANY;
> + fd = sys_perf_event_open(&attr, pid, cpu, -1, flags);
> + }
[ ... ]
> +static void probe_pmu_regs_one(const struct perf_pmu *pmu,
> + const struct perf_event_attr *base_attr,
> + pid_t pid, int cpu, unsigned long flags,
> + int max_precise, bool intr,
> + u64 *out_mask, int *out_abi,
> + u64 *out_simd_mask, u64 *out_pred_mask)
> +{
[ ... ]
> + if (EM_HOST == EM_X86_64 || EM_HOST == EM_386) {
> + int host_abi = 0;
> + u64 host_mask = intr ? perf_intr_reg_mask(EM_HOST, &host_abi) :
> + perf_user_reg_mask(EM_HOST, &host_abi);
> +
> + if ((host_abi & PERF_SAMPLE_REGS_ABI_SIMD) && (host_mask & ~gpr_mask)) {
> + u64 egpr_masks[] = { GENMASK_ULL(39, 24), BIT_ULL(40) };
[ ... ]
> + if (fd >= 0) {
> + close(fd);
> + mask |= egpr_masks[i];
> + abi |= PERF_SAMPLE_REGS_ABI_SIMD;
> + }
> + }
> + }
> + }
> +
> + if (!(abi & PERF_SAMPLE_REGS_ABI_SIMD)) {
> + u64 ext_mask = GENMASK_ULL(63, 32) & ~gpr_mask;
> + struct perf_event_attr x_attr = *base_attr;
> + bool batch_ok = false;
[Severity: Medium]
On x86_64 systems that support the SIMD register sampling ABI
(sample_simd_regs_enabled = 1) for XMM/YMM/ZMM registers but do not have APX
or CET SSP, won't this probe both legacy PEBS XMM bits (32..47) in *out_mask
and the XMM register class in *out_simd_mask?
In tools/perf/util/perf-regs-arch/perf_regs_x86.c:__perf_reg_mask_x86(),
PERF_SAMPLE_REGS_ABI_SIMD is only set in host_abi when APX (R16-R31) or CET
(SSP) is supported. Because the legacy bit 32..63 probe here checks
!(abi & PERF_SAMPLE_REGS_ABI_SIMD) before probing the SIMD vector/predicate
register classes (*out_simd_mask and *out_pred_mask) below, abi is still 0
when APX and SSP are absent, causing XMM registers to be recorded in both
intr_regs_mask and intr_simd_mask.
> +
> + x_attr.disabled = 1;
> + x_attr.sample_period = base_attr->sample_period ?: 10000;
> + x_attr.sample_type = sample_type;
> + if (intr && max_precise > 0)
> + x_attr.precise_ip = 1;
[ ... ]
> +void perf_pmu__probe(struct perf_pmu *pmu)
> +{
[ ... ]
> + /*
> + * On core PMUs, cycles/instructions may use fixed counters in addition
> + * to general-purpose (GP) programmable counters. Probe a GP-only event
> + * group rotating through distinct GP events to determine the GP limit.
> + */
> + if (pmu->is_core) {
> + static const char * const gp_events[] = {
> + "branches",
> + "branch-misses",
> + "cache-misses",
> + "cache-references",
> + "bus-cycles",
> + "stalled-cycles-frontend",
> + "stalled-cycles-backend",
> + "ref-cycles",
> + };
> + static const int gp_configs[] = {
> + PERF_COUNT_HW_BRANCH_INSTRUCTIONS,
> + PERF_COUNT_HW_BRANCH_MISSES,
> + PERF_COUNT_HW_CACHE_MISSES,
> + PERF_COUNT_HW_CACHE_REFERENCES,
> + PERF_COUNT_HW_BUS_CYCLES,
> + PERF_COUNT_HW_STALLED_CYCLES_FRONTEND,
> + PERF_COUNT_HW_STALLED_CYCLES_BACKEND,
> + PERF_COUNT_HW_REF_CPU_CYCLES,
> + };
[Severity: Medium]
Should ref-cycles / PERF_COUNT_HW_REF_CPU_CYCLES be excluded from the GP-only
probe list in perf_pmu__probe()?
On Intel core PMUs (arch/x86/events/intel/core.c,
FIXED_EVENT_CONSTRAINT(0x0300, 2)), both sysfs cpu/ref-cycles/
(event=0x00,umask=0x03) and PERF_COUNT_HW_REF_CPU_CYCLES map to
pseudo-encoding 0x0300, which is constrained exclusively to Fixed Counter 2
rather than a general-purpose counter. Including it in gp_events[] and
gp_configs[] causes Fixed Counter 2 to be allocated during the GP group
probe, inflating max_gp_group_size and max_active_gp_group_size by 1 on Intel
CPUs with >= 5 GP counters.
> + struct perf_event_attr gp_attrs[MAX_PROBE_GROUP_SIZE];
> + size_t nr_gp_attrs = 0;
[ ... ]
> diff --git a/tools/perf/util/pmus.c b/tools/perf/util/pmus.c
> index 1355b317f3eda..44f24e3a177a9 100644
> --- a/tools/perf/util/pmus.c
> +++ b/tools/perf/util/pmus.c
[ ... ]
> @@ -916,3 +940,198 @@ struct perf_pmu *perf_pmus__fake_pmu(void)
[ ... ]
> +static struct perf_pmu *env_pmu_find_or_add(const char *name, __u32 type,
> + struct perf_env *env,
> + const struct pmu_events_table *core_table)
> +{
> + struct perf_pmu *pmu = pmu_find(name);
> +
> + if (pmu) {
> + if (pmu->type == PERF_PMU_TYPE_FAKE && type != PERF_PMU_TYPE_FAKE)
> + pmu->type = type;
> + return pmu;
> + }
> +
> + pmu = zalloc(sizeof(*pmu));
> + if (!pmu)
> + return NULL;
> +
> + if (perf_pmu__init(pmu, type, name) != 0) {
> + perf_pmu__delete(pmu);
> + return NULL;
> + }
[Severity: High]
Can this trigger an out-of-bounds container_of() access and invalid free when
HEADER_PMU_MAPPINGS contains hwmon or drm PMUs?
When HEADER_PMU_MAPPINGS is written by write_pmu_mappings() or populated by
perf_env__read_pmu_mappings(), perf_pmus__scan() includes hwmon PMUs (type in
PERF_PMU_TYPE_HWMON_START..PERF_PMU_TYPE_HWMON_END) and drm PMUs (type in
PERF_PMU_TYPE_DRM_START..PERF_PMU_TYPE_DRM_END).
In perf_pmus__read_from_env() -> env_pmu_find_or_add(), pmu is allocated as a
plain struct perf_pmu via zalloc(sizeof(*pmu)) with pmu->type set to the raw
type from env->pmu_mappings. Because perf_pmu__is_hwmon() and
perf_pmu__is_drm() only check whether pmu->type falls in those ranges,
subsequent calls to perf_pmu__delete() (for example from
perf_pmus__destroy()):
if (perf_pmu__is_hwmon(pmu))
hwmon_pmu__exit(pmu);
else if (perf_pmu__is_drm(pmu))
drm_pmu__exit(pmu);
as well as perf_pmu__num_events(), perf_pmu__for_each_event(), and
perf_pmu__have_event() will dispatch to hwmon_pmu__* / drm_pmu__*, which use
container_of() to cast pmu to struct hwmon_pmu or struct drm_pmu and read or
free fields past the end of the struct perf_pmu allocation.
> +
> + pmu->sysfs_aliases_loaded = true;
> + pmu->caps_initialized = true;
> + pmu->max_precise = -1;
> + pmu->is_core = env_is_pmu_core(name, env);
> + pmu->is_uncore = strstarts(name, "uncore_");
[ ... ]
> +int perf_pmus__read_from_env(struct perf_env *env)
> +{
> + const struct pmu_events_table *core_table = NULL;
> + struct perf_pmu *pmu;
> +
> + if (!env)
> + return -EINVAL;
> +
> + perf_pmus__destroy();
> + read_pmu_types = PERF_TOOL_PMU_TYPE_ALL_MASK;
> +
> + if (env->cpuid) {
> + char cpuid_str[128];
> + char vendor[32];
> + unsigned int family, model, step;
> + const char *cpuid = env->cpuid;
> +
> + /*
> + * x86 HEADER_CPUID stores "vendor,family,model,step" in decimal
> + * while pmu-events tables match "vendor-family-HEXMODEL-HEXSTEP".
> + */
> + if (sscanf(env->cpuid, "%31[^,],%u,%u,%u",
> + vendor, &family, &model, &step) == 4) {
> + snprintf(cpuid_str, sizeof(cpuid_str), "%s-%u-%X-%X",
> + vendor, family, model, step);
> + cpuid = cpuid_str;
> + }
> + core_table = find_core_events_table(perf_env__arch(env), cpuid);
> + }
[Severity: Medium]
Does this CPUID conversion break core_table lookup on s390 and on cross-arch
analysis of x86 perf.data files?
On s390, get_cpuid() in tools/perf/arch/s390/util/header.c formats
HEADER_CPUID as "manufacturer,type,model,version,authorization" (for example,
"IBM,2964,702,3.5,002f"). Because the sscanf() call does not check that the
architecture is x86 or that the string ends after the 4th field, s390 CPUIDs
match all 4 specifiers and get rewritten to "IBM-2964-2BE-3", which fails to
match the s390 regexes in tools/perf/pmu-events/arch/s390/mapfile.csv.
Additionally, when analyzing an x86 perf.data file on a non-x86 host,
find_core_events_table() uses the generic strcmp_cpuid_str() in
tools/perf/util/header.c:
if (match) {
size_t match_len = (pmatch[0].rm_eo - pmatch[0].rm_so);
/* Verify the entire string matched. */
if (match_len == strlen(cpuid))
return 0;
}
Since most x86 entries in tools/perf/pmu-events/arch/x86/mapfile.csv are
3-field patterns without stepping (such as GenuineIntel-6-CF), won't a
4-field "%s-%u-%X-%X" string fail the match_len == strlen(cpuid) check unless
there is a 3-field "%s-%u-%X" fallback when find_core_events_table() returns
NULL?
> +
> + /* 1. Populate from HEADER_PMU_MAPPINGS */
> + if (env->nr_pmu_mappings > 0 && env->pmu_mappings) {
[ ... ]
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261016213258.945737-1-irogers@google.com?part=1
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2026-10-16 21:32 [RFC PATCH v1 0/2] perf sysinfo: Add subcommand to probe and summarize PMU capabilities Ian Rogers
2026-10-16 21:32 ` [RFC PATCH v1 1/2] perf pmus: Add PMU environment loading and live capability probing Ian Rogers
2026-10-16 21:56 ` sashiko-bot
2026-10-16 21:32 ` [RFC PATCH v1 2/2] perf sysinfo: Add sysinfo subcommand, documentation, and test Ian Rogers
2026-10-16 21:45 ` sashiko-bot
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