* [PATCH 1/5] perf stat: Constify control data for BPF
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
@ 2024-09-02 20:05 ` Namhyung Kim
2024-09-02 20:05 ` [PATCH 2/5] perf ftrace latency: " Namhyung Kim
` (4 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Namhyung Kim @ 2024-09-02 20:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Song Liu, bpf
The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/bpf_counter_cgroup.c | 6 +++---
tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/bpf_counter_cgroup.c b/tools/perf/util/bpf_counter_cgroup.c
index ea29c372f339705d..6ff42619de12bddf 100644
--- a/tools/perf/util/bpf_counter_cgroup.c
+++ b/tools/perf/util/bpf_counter_cgroup.c
@@ -61,6 +61,9 @@ static int bperf_load_program(struct evlist *evlist)
skel->rodata->num_cpus = total_cpus;
skel->rodata->num_events = evlist->core.nr_entries / nr_cgroups;
+ if (cgroup_is_v2("perf_event") > 0)
+ skel->rodata->use_cgroup_v2 = 1;
+
BUG_ON(evlist->core.nr_entries % nr_cgroups != 0);
/* we need one copy of events per cpu for reading */
@@ -82,9 +85,6 @@ static int bperf_load_program(struct evlist *evlist)
goto out;
}
- if (cgroup_is_v2("perf_event") > 0)
- skel->bss->use_cgroup_v2 = 1;
-
err = -1;
cgrp_switch = evsel__new(&cgrp_switch_attr);
diff --git a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
index 6a438e0102c5a2cb..57cab7647a9ad766 100644
--- a/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
+++ b/tools/perf/util/bpf_skel/bperf_cgroup.bpf.c
@@ -57,9 +57,9 @@ struct cgroup___old {
const volatile __u32 num_events = 1;
const volatile __u32 num_cpus = 1;
+const volatile int use_cgroup_v2 = 0;
int enabled = 0;
-int use_cgroup_v2 = 0;
int perf_subsys_id = -1;
static inline __u64 get_cgroup_v1_ancestor_id(struct cgroup *cgrp, int level)
--
2.46.0.469.g59c65b2a67-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/5] perf ftrace latency: Constify control data for BPF
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
2024-09-02 20:05 ` [PATCH 1/5] perf stat: Constify control data for BPF Namhyung Kim
@ 2024-09-02 20:05 ` Namhyung Kim
2024-09-02 20:05 ` [PATCH 3/5] perf kwork: " Namhyung Kim
` (3 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Namhyung Kim @ 2024-09-02 20:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Song Liu, bpf
The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/bpf_ftrace.c | 8 ++++----
tools/perf/util/bpf_skel/func_latency.bpf.c | 7 ++++---
2 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/tools/perf/util/bpf_ftrace.c b/tools/perf/util/bpf_ftrace.c
index 7a4297d8fd2ce925..06d1c4018407a265 100644
--- a/tools/perf/util/bpf_ftrace.c
+++ b/tools/perf/util/bpf_ftrace.c
@@ -40,13 +40,17 @@ int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
if (ftrace->target.cpu_list) {
ncpus = perf_cpu_map__nr(ftrace->evlist->core.user_requested_cpus);
bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
+ skel->rodata->has_cpu = 1;
}
if (target__has_task(&ftrace->target) || target__none(&ftrace->target)) {
ntasks = perf_thread_map__nr(ftrace->evlist->core.threads);
bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
+ skel->rodata->has_task = 1;
}
+ skel->rodata->use_nsec = ftrace->use_nsec;
+
set_max_rlimit();
err = func_latency_bpf__load(skel);
@@ -59,7 +63,6 @@ int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
u32 cpu;
u8 val = 1;
- skel->bss->has_cpu = 1;
fd = bpf_map__fd(skel->maps.cpu_filter);
for (i = 0; i < ncpus; i++) {
@@ -72,7 +75,6 @@ int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
u32 pid;
u8 val = 1;
- skel->bss->has_task = 1;
fd = bpf_map__fd(skel->maps.task_filter);
for (i = 0; i < ntasks; i++) {
@@ -81,8 +83,6 @@ int perf_ftrace__latency_prepare_bpf(struct perf_ftrace *ftrace)
}
}
- skel->bss->use_nsec = ftrace->use_nsec;
-
skel->links.func_begin = bpf_program__attach_kprobe(skel->progs.func_begin,
false, func->name);
if (IS_ERR(skel->links.func_begin)) {
diff --git a/tools/perf/util/bpf_skel/func_latency.bpf.c b/tools/perf/util/bpf_skel/func_latency.bpf.c
index 9d01e3af747922ca..f613dc9cb123480c 100644
--- a/tools/perf/util/bpf_skel/func_latency.bpf.c
+++ b/tools/perf/util/bpf_skel/func_latency.bpf.c
@@ -37,9 +37,10 @@ struct {
int enabled = 0;
-int has_cpu = 0;
-int has_task = 0;
-int use_nsec = 0;
+
+const volatile int has_cpu = 0;
+const volatile int has_task = 0;
+const volatile int use_nsec = 0;
SEC("kprobe/func")
int BPF_PROG(func_begin)
--
2.46.0.469.g59c65b2a67-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 3/5] perf kwork: Constify control data for BPF
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
2024-09-02 20:05 ` [PATCH 1/5] perf stat: Constify control data for BPF Namhyung Kim
2024-09-02 20:05 ` [PATCH 2/5] perf ftrace latency: " Namhyung Kim
@ 2024-09-02 20:05 ` Namhyung Kim
2024-09-02 20:05 ` [PATCH 4/5] perf lock contention: " Namhyung Kim
` (2 subsequent siblings)
5 siblings, 0 replies; 7+ messages in thread
From: Namhyung Kim @ 2024-09-02 20:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Song Liu, bpf, Yang Jihong
The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.
Cc: Yang Jihong <yangjihong@bytedance.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/bpf_kwork.c | 9 +++++----
tools/perf/util/bpf_kwork_top.c | 7 ++++---
tools/perf/util/bpf_skel/kwork_top.bpf.c | 2 +-
tools/perf/util/bpf_skel/kwork_trace.bpf.c | 5 +++--
4 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/tools/perf/util/bpf_kwork.c b/tools/perf/util/bpf_kwork.c
index 44f0f708a15d6a14..6c7126b7670dd0c9 100644
--- a/tools/perf/util/bpf_kwork.c
+++ b/tools/perf/util/bpf_kwork.c
@@ -176,8 +176,6 @@ static int setup_filters(struct perf_kwork *kwork)
bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY);
}
perf_cpu_map__put(map);
-
- skel->bss->has_cpu_filter = 1;
}
if (kwork->profile_name != NULL) {
@@ -197,8 +195,6 @@ static int setup_filters(struct perf_kwork *kwork)
key = 0;
bpf_map_update_elem(fd, &key, kwork->profile_name, BPF_ANY);
-
- skel->bss->has_name_filter = 1;
}
return 0;
@@ -239,6 +235,11 @@ int perf_kwork__trace_prepare_bpf(struct perf_kwork *kwork)
class_bpf->load_prepare(kwork);
}
+ if (kwork->cpu_list != NULL)
+ skel->rodata->has_cpu_filter = 1;
+ if (kwork->profile_name != NULL)
+ skel->rodata->has_name_filter = 1;
+
if (kwork_trace_bpf__load(skel)) {
pr_debug("Failed to load kwork trace skeleton\n");
goto out;
diff --git a/tools/perf/util/bpf_kwork_top.c b/tools/perf/util/bpf_kwork_top.c
index 22a3b00a1e23f929..7261cad43468d7a4 100644
--- a/tools/perf/util/bpf_kwork_top.c
+++ b/tools/perf/util/bpf_kwork_top.c
@@ -151,14 +151,12 @@ static int setup_filters(struct perf_kwork *kwork)
bpf_map_update_elem(fd, &cpu.cpu, &val, BPF_ANY);
}
perf_cpu_map__put(map);
-
- skel->bss->has_cpu_filter = 1;
}
return 0;
}
-int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork __maybe_unused)
+int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork)
{
struct bpf_program *prog;
struct kwork_class *class;
@@ -193,6 +191,9 @@ int perf_kwork__top_prepare_bpf(struct perf_kwork *kwork __maybe_unused)
class_bpf->load_prepare();
}
+ if (kwork->cpu_list)
+ skel->rodata->has_cpu_filter = 1;
+
if (kwork_top_bpf__load(skel)) {
pr_debug("Failed to load kwork top skeleton\n");
goto out;
diff --git a/tools/perf/util/bpf_skel/kwork_top.bpf.c b/tools/perf/util/bpf_skel/kwork_top.bpf.c
index 84c15ccbab44ccc9..594da91965a2f6c9 100644
--- a/tools/perf/util/bpf_skel/kwork_top.bpf.c
+++ b/tools/perf/util/bpf_skel/kwork_top.bpf.c
@@ -84,7 +84,7 @@ struct {
int enabled = 0;
-int has_cpu_filter = 0;
+const volatile int has_cpu_filter = 0;
__u64 from_timestamp = 0;
__u64 to_timestamp = 0;
diff --git a/tools/perf/util/bpf_skel/kwork_trace.bpf.c b/tools/perf/util/bpf_skel/kwork_trace.bpf.c
index 063c124e099938ed..cbd79bc4b3302d81 100644
--- a/tools/perf/util/bpf_skel/kwork_trace.bpf.c
+++ b/tools/perf/util/bpf_skel/kwork_trace.bpf.c
@@ -68,8 +68,9 @@ struct {
} perf_kwork_name_filter SEC(".maps");
int enabled = 0;
-int has_cpu_filter = 0;
-int has_name_filter = 0;
+
+const volatile int has_cpu_filter = 0;
+const volatile int has_name_filter = 0;
static __always_inline int local_strncmp(const char *s1,
unsigned int sz, const char *s2)
--
2.46.0.469.g59c65b2a67-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 4/5] perf lock contention: Constify control data for BPF
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
` (2 preceding siblings ...)
2024-09-02 20:05 ` [PATCH 3/5] perf kwork: " Namhyung Kim
@ 2024-09-02 20:05 ` Namhyung Kim
2024-09-02 20:05 ` [PATCH 5/5] perf record offcpu: " Namhyung Kim
2024-09-03 15:18 ` [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Arnaldo Carvalho de Melo
5 siblings, 0 replies; 7+ messages in thread
From: Namhyung Kim @ 2024-09-02 20:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Song Liu, bpf
The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/bpf_lock_contention.c | 45 ++++++++++---------
.../perf/util/bpf_skel/lock_contention.bpf.c | 27 +++++------
2 files changed, 38 insertions(+), 34 deletions(-)
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index bc4e92c0c08b8b20..41a1ad08789511c3 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -46,14 +46,22 @@ int lock_contention_prepare(struct lock_contention *con)
else
bpf_map__set_max_entries(skel->maps.stacks, 1);
- if (target__has_cpu(target))
+ if (target__has_cpu(target)) {
+ skel->rodata->has_cpu = 1;
ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus);
- if (target__has_task(target))
+ }
+ if (target__has_task(target)) {
+ skel->rodata->has_task = 1;
ntasks = perf_thread_map__nr(evlist->core.threads);
- if (con->filters->nr_types)
+ }
+ if (con->filters->nr_types) {
+ skel->rodata->has_type = 1;
ntypes = con->filters->nr_types;
- if (con->filters->nr_cgrps)
+ }
+ if (con->filters->nr_cgrps) {
+ skel->rodata->has_cgroup = 1;
ncgrps = con->filters->nr_cgrps;
+ }
/* resolve lock name filters to addr */
if (con->filters->nr_syms) {
@@ -82,6 +90,7 @@ int lock_contention_prepare(struct lock_contention *con)
con->filters->addrs = addrs;
}
naddrs = con->filters->nr_addrs;
+ skel->rodata->has_addr = 1;
}
bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
@@ -90,6 +99,16 @@ int lock_contention_prepare(struct lock_contention *con)
bpf_map__set_max_entries(skel->maps.addr_filter, naddrs);
bpf_map__set_max_entries(skel->maps.cgroup_filter, ncgrps);
+ skel->rodata->stack_skip = con->stack_skip;
+ skel->rodata->aggr_mode = con->aggr_mode;
+ skel->rodata->needs_callstack = con->save_callstack;
+ skel->rodata->lock_owner = con->owner;
+
+ if (con->aggr_mode == LOCK_AGGR_CGROUP || con->filters->nr_cgrps) {
+ if (cgroup_is_v2("perf_event"))
+ skel->rodata->use_cgroup_v2 = 1;
+ }
+
if (lock_contention_bpf__load(skel) < 0) {
pr_err("Failed to load lock-contention BPF skeleton\n");
return -1;
@@ -99,7 +118,6 @@ int lock_contention_prepare(struct lock_contention *con)
u32 cpu;
u8 val = 1;
- skel->bss->has_cpu = 1;
fd = bpf_map__fd(skel->maps.cpu_filter);
for (i = 0; i < ncpus; i++) {
@@ -112,7 +130,6 @@ int lock_contention_prepare(struct lock_contention *con)
u32 pid;
u8 val = 1;
- skel->bss->has_task = 1;
fd = bpf_map__fd(skel->maps.task_filter);
for (i = 0; i < ntasks; i++) {
@@ -125,7 +142,6 @@ int lock_contention_prepare(struct lock_contention *con)
u32 pid = evlist->workload.pid;
u8 val = 1;
- skel->bss->has_task = 1;
fd = bpf_map__fd(skel->maps.task_filter);
bpf_map_update_elem(fd, &pid, &val, BPF_ANY);
}
@@ -133,7 +149,6 @@ int lock_contention_prepare(struct lock_contention *con)
if (con->filters->nr_types) {
u8 val = 1;
- skel->bss->has_type = 1;
fd = bpf_map__fd(skel->maps.type_filter);
for (i = 0; i < con->filters->nr_types; i++)
@@ -143,7 +158,6 @@ int lock_contention_prepare(struct lock_contention *con)
if (con->filters->nr_addrs) {
u8 val = 1;
- skel->bss->has_addr = 1;
fd = bpf_map__fd(skel->maps.addr_filter);
for (i = 0; i < con->filters->nr_addrs; i++)
@@ -153,25 +167,14 @@ int lock_contention_prepare(struct lock_contention *con)
if (con->filters->nr_cgrps) {
u8 val = 1;
- skel->bss->has_cgroup = 1;
fd = bpf_map__fd(skel->maps.cgroup_filter);
for (i = 0; i < con->filters->nr_cgrps; i++)
bpf_map_update_elem(fd, &con->filters->cgrps[i], &val, BPF_ANY);
}
- /* these don't work well if in the rodata section */
- skel->bss->stack_skip = con->stack_skip;
- skel->bss->aggr_mode = con->aggr_mode;
- skel->bss->needs_callstack = con->save_callstack;
- skel->bss->lock_owner = con->owner;
-
- if (con->aggr_mode == LOCK_AGGR_CGROUP) {
- if (cgroup_is_v2("perf_event"))
- skel->bss->use_cgroup_v2 = 1;
-
+ if (con->aggr_mode == LOCK_AGGR_CGROUP)
read_all_cgroups(&con->cgroups);
- }
bpf_program__set_autoload(skel->progs.collect_lock_syms, false);
diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
index 52a876b4269917fe..1069bda5d733887f 100644
--- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
+++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
@@ -117,21 +117,22 @@ struct mm_struct___new {
} __attribute__((preserve_access_index));
/* control flags */
-int enabled;
-int has_cpu;
-int has_task;
-int has_type;
-int has_addr;
-int has_cgroup;
-int needs_callstack;
-int stack_skip;
-int lock_owner;
-
-int use_cgroup_v2;
-int perf_subsys_id = -1;
+const volatile int has_cpu;
+const volatile int has_task;
+const volatile int has_type;
+const volatile int has_addr;
+const volatile int has_cgroup;
+const volatile int needs_callstack;
+const volatile int stack_skip;
+const volatile int lock_owner;
+const volatile int use_cgroup_v2;
/* determine the key of lock stat */
-int aggr_mode;
+const volatile int aggr_mode;
+
+int enabled;
+
+int perf_subsys_id = -1;
__u64 end_ts;
--
2.46.0.469.g59c65b2a67-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 5/5] perf record offcpu: Constify control data for BPF
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
` (3 preceding siblings ...)
2024-09-02 20:05 ` [PATCH 4/5] perf lock contention: " Namhyung Kim
@ 2024-09-02 20:05 ` Namhyung Kim
2024-09-03 15:18 ` [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Arnaldo Carvalho de Melo
5 siblings, 0 replies; 7+ messages in thread
From: Namhyung Kim @ 2024-09-02 20:05 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo, Ian Rogers, Kan Liang
Cc: Jiri Olsa, Adrian Hunter, Peter Zijlstra, Ingo Molnar, LKML,
linux-perf-users, Song Liu, bpf
The control knobs set before loading BPF programs should be declared as
'const volatile' so that it can be optimized by the BPF core.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/perf/util/bpf_off_cpu.c | 16 ++++++++--------
tools/perf/util/bpf_skel/off_cpu.bpf.c | 9 +++++----
2 files changed, 13 insertions(+), 12 deletions(-)
diff --git a/tools/perf/util/bpf_off_cpu.c b/tools/perf/util/bpf_off_cpu.c
index 6af36142dc5a7fd0..a590a8ac1f9d42f0 100644
--- a/tools/perf/util/bpf_off_cpu.c
+++ b/tools/perf/util/bpf_off_cpu.c
@@ -73,14 +73,12 @@ static void off_cpu_start(void *arg)
struct evlist *evlist = arg;
/* update task filter for the given workload */
- if (!skel->bss->has_cpu && !skel->bss->has_task &&
+ if (skel->rodata->has_task && skel->rodata->uses_tgid &&
perf_thread_map__pid(evlist->core.threads, 0) != -1) {
int fd;
u32 pid;
u8 val = 1;
- skel->bss->has_task = 1;
- skel->bss->uses_tgid = 1;
fd = bpf_map__fd(skel->maps.task_filter);
pid = perf_thread_map__pid(evlist->core.threads, 0);
bpf_map_update_elem(fd, &pid, &val, BPF_ANY);
@@ -148,6 +146,7 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
if (target->cpu_list) {
ncpus = perf_cpu_map__nr(evlist->core.user_requested_cpus);
bpf_map__set_max_entries(skel->maps.cpu_filter, ncpus);
+ skel->rodata->has_cpu = 1;
}
if (target->pid) {
@@ -173,11 +172,16 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
ntasks = MAX_PROC;
bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
+ skel->rodata->has_task = 1;
+ skel->rodata->uses_tgid = 1;
} else if (target__has_task(target)) {
ntasks = perf_thread_map__nr(evlist->core.threads);
bpf_map__set_max_entries(skel->maps.task_filter, ntasks);
+ skel->rodata->has_task = 1;
} else if (target__none(target)) {
bpf_map__set_max_entries(skel->maps.task_filter, MAX_PROC);
+ skel->rodata->has_task = 1;
+ skel->rodata->uses_tgid = 1;
}
if (evlist__first(evlist)->cgrp) {
@@ -186,6 +190,7 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
if (!cgroup_is_v2("perf_event"))
skel->rodata->uses_cgroup_v1 = true;
+ skel->rodata->has_cgroup = 1;
}
if (opts->record_cgroup) {
@@ -208,7 +213,6 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
u32 cpu;
u8 val = 1;
- skel->bss->has_cpu = 1;
fd = bpf_map__fd(skel->maps.cpu_filter);
for (i = 0; i < ncpus; i++) {
@@ -220,8 +224,6 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
if (target->pid) {
u8 val = 1;
- skel->bss->has_task = 1;
- skel->bss->uses_tgid = 1;
fd = bpf_map__fd(skel->maps.task_filter);
strlist__for_each_entry(pos, pid_slist) {
@@ -240,7 +242,6 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
u32 pid;
u8 val = 1;
- skel->bss->has_task = 1;
fd = bpf_map__fd(skel->maps.task_filter);
for (i = 0; i < ntasks; i++) {
@@ -253,7 +254,6 @@ int off_cpu_prepare(struct evlist *evlist, struct target *target,
struct evsel *evsel;
u8 val = 1;
- skel->bss->has_cgroup = 1;
fd = bpf_map__fd(skel->maps.cgroup_filter);
evlist__for_each_entry(evlist, evsel) {
diff --git a/tools/perf/util/bpf_skel/off_cpu.bpf.c b/tools/perf/util/bpf_skel/off_cpu.bpf.c
index d877a0a9731f9f2f..c152116df72f9bc1 100644
--- a/tools/perf/util/bpf_skel/off_cpu.bpf.c
+++ b/tools/perf/util/bpf_skel/off_cpu.bpf.c
@@ -85,10 +85,11 @@ struct task_struct___old {
} __attribute__((preserve_access_index));
int enabled = 0;
-int has_cpu = 0;
-int has_task = 0;
-int has_cgroup = 0;
-int uses_tgid = 0;
+
+const volatile int has_cpu = 0;
+const volatile int has_task = 0;
+const volatile int has_cgroup = 0;
+const volatile int uses_tgid = 0;
const volatile bool has_prev_state = false;
const volatile bool needs_cgroup = false;
--
2.46.0.469.g59c65b2a67-goog
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1)
2024-09-02 20:05 [PATCHSET 0/5] perf tools: Constify BPF control data properly (v1) Namhyung Kim
` (4 preceding siblings ...)
2024-09-02 20:05 ` [PATCH 5/5] perf record offcpu: " Namhyung Kim
@ 2024-09-03 15:18 ` Arnaldo Carvalho de Melo
5 siblings, 0 replies; 7+ messages in thread
From: Arnaldo Carvalho de Melo @ 2024-09-03 15:18 UTC (permalink / raw)
To: Namhyung Kim
Cc: Ian Rogers, Kan Liang, Jiri Olsa, Adrian Hunter, Peter Zijlstra,
Ingo Molnar, LKML, linux-perf-users, Song Liu, bpf
On Mon, Sep 02, 2024 at 01:05:10PM -0700, Namhyung Kim wrote:
> Hello,
>
> I've realized that some control data (usually for filter actions)
> should be defined as 'const volatile' so that it can passed to the BPF
> core and to be optimized properly (like with dead code elimination).
>
> Convert the existing codes with the similar patterns.
Thanks, tested all the features using BPF, applied to perf-tools-next,
- Arnaldo
> Thanks,
> Namhyung
>
>
> Namhyung Kim (5):
> perf stat: Constify control data for BPF
> perf ftrace latency: Constify control data for BPF
> perf kwork: Constify control data for BPF
> perf lock contention: Constify control data for BPF
> perf record offcpu: Constify control data for BPF
>
> tools/perf/util/bpf_counter_cgroup.c | 6 +--
> tools/perf/util/bpf_ftrace.c | 8 ++--
> tools/perf/util/bpf_kwork.c | 9 ++--
> tools/perf/util/bpf_kwork_top.c | 7 +--
> tools/perf/util/bpf_lock_contention.c | 45 ++++++++++---------
> tools/perf/util/bpf_off_cpu.c | 16 +++----
> tools/perf/util/bpf_skel/bperf_cgroup.bpf.c | 2 +-
> tools/perf/util/bpf_skel/func_latency.bpf.c | 7 +--
> tools/perf/util/bpf_skel/kwork_top.bpf.c | 2 +-
> tools/perf/util/bpf_skel/kwork_trace.bpf.c | 5 ++-
> .../perf/util/bpf_skel/lock_contention.bpf.c | 27 +++++------
> tools/perf/util/bpf_skel/off_cpu.bpf.c | 9 ++--
> 12 files changed, 76 insertions(+), 67 deletions(-)
>
> --
> 2.46.0.469.g59c65b2a67-goog
^ permalink raw reply [flat|nested] 7+ messages in thread