[PATCH v2 12/16] perf lock: Move common lock contention code to new file

Ian Rogers
2024-10-16T04:25:03Z

Avoid references from util code to builtin-lock that require python
stubs. Move the functions and related variables to
util/lock-contention.c. Add max_stack_depth parameter to
match_callstack_filter to avoid sharing a global variable.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/builtin-lock.c | 137 +--------------------
tools/perf/util/Build | 1 +
tools/perf/util/bpf_lock_contention.c | 2 +-
tools/perf/util/lock-contention.c | 170 ++++++++++++++++++++++++++
tools/perf/util/lock-contention.h | 37 ++----
tools/perf/util/python.c | 17 ---
6 files changed, 185 insertions(+), 179 deletions(-)
create mode 100644 tools/perf/util/lock-contention.c

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 062e2b56a2ab..f66948b1fbed 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -46,15 +46,6 @@
static struct perf_session *session;
static struct target target;

-/* based on kernel/lockdep.c */
-#define LOCKHASH_BITS 12
-#define LOCKHASH_SIZE (1UL << LOCKHASH_BITS)
-
-static struct hlist_head *lockhash_table;
-
-#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
-#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))
-
static struct rb_root thread_stats;

static bool combine_locks;
@@ -67,24 +58,13 @@ static unsigned long bpf_map_entries = MAX_ENTRIES;
static int max_stack_depth = CONTENTION_STACK_DEPTH;
static int stack_skip = CONTENTION_STACK_SKIP;
static int print_nr_entries = INT_MAX / 2;
-static LIST_HEAD(callstack_filters);
static const char *output_name = NULL;
static FILE *lock_output;

-struct callstack_filter {
- struct list_head list;
- char name[];
-};
-
static struct lock_filter filters;

static enum lock_aggr_mode aggr_mode = LOCK_AGGR_ADDR;

-static bool needs_callstack(void)
-{
- return !list_empty(&callstack_filters);
-}
-
static struct thread_stat *thread_stat_find(u32 tid)
{
struct rb_node *node;
@@ -477,93 +457,6 @@ static struct lock_stat *pop_from_result(void)
return container_of(node, struct lock_stat, rb);
}

-struct lock_stat *lock_stat_find(u64 addr)
-{
- struct hlist_head *entry = lockhashentry(addr);
- struct lock_stat *ret;
-
- hlist_for_each_entry(ret, entry, hash_entry) {
- if (ret->addr == addr)
- return ret;
- }
- return NULL;
-}
-
-struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)
-{
- struct hlist_head *entry = lockhashentry(addr);
- struct lock_stat *ret, *new;
-
- hlist_for_each_entry(ret, entry, hash_entry) {
- if (ret->addr == addr)
- return ret;
- }
-
- new = zalloc(sizeof(struct lock_stat));
- if (!new)
- goto alloc_failed;
-
- new->addr = addr;
- new->name = strdup(name);
- if (!new->name) {
- free(new);
- goto alloc_failed;
- }
-
- new->flags = flags;
- new->wait_time_min = ULLONG_MAX;
-
- hlist_add_head(&new->hash_entry, entry);
- return new;
-
-alloc_failed:
- pr_err("memory allocation failed\n");
- return NULL;
-}
-
-bool match_callstack_filter(struct machine *machine, u64 *callstack)
-{
- struct map *kmap;
- struct symbol *sym;
- u64 ip;
- const char *arch = perf_env__arch(machine->env);
-
- if (list_empty(&callstack_filters))
- return true;
-
- for (int i = 0; i < max_stack_depth; i++) {
- struct callstack_filter *filter;
-
- /*
- * In powerpc, the callchain saved by kernel always includes
- * first three entries as the NIP (next instruction pointer),
- * LR (link register), and the contents of LR save area in the
- * second stack frame. In certain scenarios its possible to have
- * invalid kernel instruction addresses in either LR or the second
- * stack frame's LR. In that case, kernel will store that address as
- * zero.
- *
- * The below check will continue to look into callstack,
- * incase first or second callstack index entry has 0
- * address for powerpc.
- */
- if (!callstack || (!callstack[i] && (strcmp(arch, "powerpc") ||
- (i != 1 && i != 2))))
- break;
-
- ip = callstack[i];
- sym = machine__find_kernel_symbol(machine, ip, &kmap);
- if (sym == NULL)
- continue;
-
- list_for_each_entry(filter, &callstack_filters, list) {
- if (strstr(sym->name, filter->name))
- return true;
- }
- }
- return false;
-}
-
struct trace_lock_handler {
/* it's used on CONFIG_LOCKDEP */
int (*acquire_event)(struct evsel *evsel,
@@ -1165,7 +1058,7 @@ static int report_lock_contention_begin_event(struct evsel *evsel,
if (callstack == NULL)
return -ENOMEM;

- if (!match_callstack_filter(machine, callstack)) {
+ if (!match_callstack_filter(machine, callstack, max_stack_depth)) {
free(callstack);
return 0;
}
@@ -2449,34 +2342,6 @@ static int parse_lock_addr(const struct option *opt __maybe_unused, const char *
return ret;
}

-static int parse_call_stack(const struct option *opt __maybe_unused, const char *str,
- int unset __maybe_unused)
-{
- char *s, *tmp, *tok;
- int ret = 0;
-
- s = strdup(str);
- if (s == NULL)
- return -1;
-
- for (tok = strtok_r(s, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {
- struct callstack_filter *entry;
-
- entry = malloc(sizeof(*entry) + strlen(tok) + 1);
- if (entry == NULL) {
- pr_err("Memory allocation failure\n");
- free(s);
- return -1;
- }
-
- strcpy(entry->name, tok);
- list_add_tail(&entry->list, &callstack_filters);
- }
-
- free(s);
- return ret;
-}
-
static int parse_output(const struct option *opt __maybe_unused, const char *str,
int unset __maybe_unused)
{
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 2a2f7780e595..ea2d9eced92e 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -121,6 +121,7 @@ perf-util-y += topdown.o
perf-util-y += iostat.o
perf-util-y += stream.o
perf-util-y += kvm-stat.o
+perf-util-y += lock-contention.o
perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
perf-util-$(CONFIG_AUXTRACE) += intel-pt-decoder/
perf-util-$(CONFIG_AUXTRACE) += intel-pt.o
diff --git a/tools/perf/util/bpf_lock_contention.c b/tools/perf/util/bpf_lock_contention.c
index 41a1ad087895..37e17c56f106 100644
--- a/tools/perf/util/bpf_lock_contention.c
+++ b/tools/perf/util/bpf_lock_contention.c
@@ -458,7 +458,7 @@ int lock_contention_read(struct lock_contention *con)
if (con->save_callstack) {
bpf_map_lookup_elem(stack, &key.stack_id, stack_trace);

- if (!match_callstack_filter(machine, stack_trace)) {
+ if (!match_callstack_filter(machine, stack_trace, con->max_stack)) {
con->nr_filtered += data.count;
goto next;
}
diff --git a/tools/perf/util/lock-contention.c b/tools/perf/util/lock-contention.c
new file mode 100644
index 000000000000..841bb18b1f06
--- /dev/null
+++ b/tools/perf/util/lock-contention.c
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "debug.h"
+#include "env.h"
+#include "lock-contention.h"
+#include "machine.h"
+#include "symbol.h"
+
+#include <limits.h>
+#include <string.h>
+
+#include <linux/hash.h>
+#include <linux/zalloc.h>
+
+#define __lockhashfn(key) hash_long((unsigned long)key, LOCKHASH_BITS)
+#define lockhashentry(key) (lockhash_table + __lockhashfn((key)))
+
+struct callstack_filter {
+ struct list_head list;
+ char name[];
+};
+
+static LIST_HEAD(callstack_filters);
+struct hlist_head *lockhash_table;
+
+int parse_call_stack(const struct option *opt __maybe_unused, const char *str,
+ int unset __maybe_unused)
+{
+ char *s, *tmp, *tok;
+ int ret = 0;
+
+ s = strdup(str);
+ if (s == NULL)
+ return -1;
+
+ for (tok = strtok_r(s, ", ", &tmp); tok; tok = strtok_r(NULL, ", ", &tmp)) {
+ struct callstack_filter *entry;
+
+ entry = malloc(sizeof(*entry) + strlen(tok) + 1);
+ if (entry == NULL) {
+ pr_err("Memory allocation failure\n");
+ free(s);
+ return -1;
+ }
+
+ strcpy(entry->name, tok);
+ list_add_tail(&entry->list, &callstack_filters);
+ }
+
+ free(s);
+ return ret;
+}
+
+bool needs_callstack(void)
+{
+ return !list_empty(&callstack_filters);
+}
+
+struct lock_stat *lock_stat_find(u64 addr)
+{
+ struct hlist_head *entry = lockhashentry(addr);
+ struct lock_stat *ret;
+
+ hlist_for_each_entry(ret, entry, hash_entry) {
+ if (ret->addr == addr)
+ return ret;
+ }
+ return NULL;
+}
+
+struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags)
+{
+ struct hlist_head *entry = lockhashentry(addr);
+ struct lock_stat *ret, *new;
+
+ hlist_for_each_entry(ret, entry, hash_entry) {
+ if (ret->addr == addr)
+ return ret;
+ }
+
+ new = zalloc(sizeof(struct lock_stat));
+ if (!new)
+ goto alloc_failed;
+
+ new->addr = addr;
+ new->name = strdup(name);
+ if (!new->name) {
+ free(new);
+ goto alloc_failed;
+ }
+
+ new->flags = flags;
+ new->wait_time_min = ULLONG_MAX;
+
+ hlist_add_head(&new->hash_entry, entry);
+ return new;
+
+alloc_failed:
+ pr_err("memory allocation failed\n");
+ return NULL;
+}
+
+bool match_callstack_filter(struct machine *machine, u64 *callstack, int max_stack_depth)
+{
+ struct map *kmap;
+ struct symbol *sym;
+ u64 ip;
+ const char *arch = perf_env__arch(machine->env);
+
+ if (list_empty(&callstack_filters))
+ return true;
+
+ for (int i = 0; i < max_stack_depth; i++) {
+ struct callstack_filter *filter;
+
+ /*
+ * In powerpc, the callchain saved by kernel always includes
+ * first three entries as the NIP (next instruction pointer),
+ * LR (link register), and the contents of LR save area in the
+ * second stack frame. In certain scenarios its possible to have
+ * invalid kernel instruction addresses in either LR or the second
+ * stack frame's LR. In that case, kernel will store that address as
+ * zero.
+ *
+ * The below check will continue to look into callstack,
+ * incase first or second callstack index entry has 0
+ * address for powerpc.
+ */
+ if (!callstack || (!callstack[i] && (strcmp(arch, "powerpc") ||
+ (i != 1 && i != 2))))
+ break;
+
+ ip = callstack[i];
+ sym = machine__find_kernel_symbol(machine, ip, &kmap);
+ if (sym == NULL)
+ continue;
+
+ list_for_each_entry(filter, &callstack_filters, list) {
+ if (strstr(sym->name, filter->name))
+ return true;
+ }
+ }
+ return false;
+}
+
+#ifndef HAVE_BPF_SKEL
+int lock_contention_prepare(struct lock_contention *con __maybe_unused)
+{
+ return 0;
+}
+
+int lock_contention_start(void)
+{
+ return 0;
+}
+
+int lock_contention_stop(void)
+{
+ return 0;
+}
+
+int lock_contention_finish(struct lock_contention *con __maybe_unused)
+{
+ return 0;
+}
+
+int lock_contention_read(struct lock_contention *con __maybe_unused)
+{
+ return 0;
+}
+#endif /* !HAVE_BPF_SKEL */
diff --git a/tools/perf/util/lock-contention.h b/tools/perf/util/lock-contention.h
index 1a7248ff3889..bfa5c7db0a5d 100644
--- a/tools/perf/util/lock-contention.h
+++ b/tools/perf/util/lock-contention.h
@@ -67,10 +67,11 @@ struct lock_stat {
*/
#define MAX_LOCK_DEPTH 48

-struct lock_stat *lock_stat_find(u64 addr);
-struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);
+/* based on kernel/lockdep.c */
+#define LOCKHASH_BITS 12
+#define LOCKHASH_SIZE (1UL << LOCKHASH_BITS)

-bool match_callstack_filter(struct machine *machine, u64 *callstack);
+extern struct hlist_head *lockhash_table;

/*
* struct lock_seq_stat:
@@ -148,7 +149,14 @@ struct lock_contention {
bool save_callstack;
};

-#ifdef HAVE_BPF_SKEL
+struct option;
+int parse_call_stack(const struct option *opt, const char *str, int unset);
+bool needs_callstack(void);
+
+struct lock_stat *lock_stat_find(u64 addr);
+struct lock_stat *lock_stat_findnew(u64 addr, const char *name, int flags);
+
+bool match_callstack_filter(struct machine *machine, u64 *callstack, int max_stack_depth);

int lock_contention_prepare(struct lock_contention *con);
int lock_contention_start(void);
@@ -156,25 +164,4 @@ int lock_contention_stop(void);
int lock_contention_read(struct lock_contention *con);
int lock_contention_finish(struct lock_contention *con);

-#else /* !HAVE_BPF_SKEL */
-
-static inline int lock_contention_prepare(struct lock_contention *con __maybe_unused)
-{
- return 0;
-}
-
-static inline int lock_contention_start(void) { return 0; }
-static inline int lock_contention_stop(void) { return 0; }
-static inline int lock_contention_finish(struct lock_contention *con __maybe_unused)
-{
- return 0;
-}
-
-static inline int lock_contention_read(struct lock_contention *con __maybe_unused)
-{
- return 0;
-}
-
-#endif /* HAVE_BPF_SKEL */
-
#endif /* PERF_LOCK_CONTENTION_H */
diff --git a/tools/perf/util/python.c b/tools/perf/util/python.c
index 35d84a96dbec..91fd444615cd 100644
--- a/tools/perf/util/python.c
+++ b/tools/perf/util/python.c
@@ -18,7 +18,6 @@
#include "mmap.h"
#include "util/kwork.h"
#include "util/sample.h"
-#include "util/lock-contention.h"
#include <internal/lib.h>
#include "../builtin.h"

@@ -1311,22 +1310,6 @@ struct kwork_work *perf_kwork_add_work(struct perf_kwork *kwork __maybe_unused,
return NULL;
}

-bool match_callstack_filter(struct machine *machine __maybe_unused, u64 *callstack __maybe_unused)
-{
- return false;
-}
-
-struct lock_stat *lock_stat_find(u64 addr __maybe_unused)
-{
- return NULL;
-}
-
-struct lock_stat *lock_stat_findnew(u64 addr __maybe_unused, const char *name __maybe_unused,
- int flags __maybe_unused)
-{
- return NULL;
-}
-
int cmd_inject(int argc __maybe_unused, const char *argv[] __maybe_unused)
{
return -1;
--
2.47.0.rc1.288.g06298d1525-goog