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Message-ID: <20241126212255.3793822-2-ctshao@google.com>
Date: Tue, 26 Nov 2024 13:22:54 -0800
From: Chun-Tse Shao <ctshao@...gle.com>
To: linux-kernel@...r.kernel.org
Cc: Chun-Tse Shao <ctshao@...gle.com>, peterz@...radead.org, mingo@...hat.com,
acme@...nel.org, namhyung@...nel.org, mark.rutland@....com,
alexander.shishkin@...ux.intel.com, jolsa@...nel.org, irogers@...gle.com,
adrian.hunter@...el.com, kan.liang@...ux.intel.com,
linux-perf-users@...r.kernel.org
Subject: [PATCH v3 2/2] perf lock: Fix parse_lock_type which only retrieve one
lock flag
`parse_lock_type` can only add the first lock flag in `lock_type_table`
given input `str`. For example, for `Y rwlock`, it only adds `rwlock:R`
into this perf session. Another example is for `-Y mutex`, it only adds
the mutex without `LCB_F_SPIN` flag. The patch fixes this issue, makes
sure both `rwlock:R` and `rwlock:W` will be added with `-Y rwlock`, and
so on.
Testing:
$ ./perf lock con -ab -Y mutex,rwlock -- perf bench sched pipe
# Running 'sched/pipe' benchmark:
# Executed 1000000 pipe operations between two processes
Total time: 8.425 [sec]
8.425402 usecs/op
118688 ops/sec
contended total wait max wait avg wait type caller
194 1.68 ms 44.16 us 8.66 us mutex pipe_read+0x57
10 423.03 us 44.27 us 42.30 us rwlock:W do_exit+0x365
54 254.67 us 58.87 us 4.72 us mutex pipe_write+0x50
21 146.64 us 11.54 us 6.98 us mutex pipe_read+0x282
10 141.27 us 20.62 us 14.13 us rwlock:W release_task+0x6f
5 58.92 us 16.37 us 11.78 us mutex do_epoll_wait+0x24d
3 29.81 us 17.66 us 9.94 us mutex do_epoll_ctl+0x6c1
4 26.82 us 11.02 us 6.70 us mutex do_epoll_wait+0x24d
2 18.32 us 12.49 us 9.16 us rwlock:W do_epoll_wait+0x255
1 11.34 us 11.34 us 11.34 us rwlock:W ep_done_scan+0x2d
1 11.02 us 11.02 us 11.02 us rwlock:R mm_update_next_owner+0x4e
1 10.60 us 10.60 us 10.60 us rwlock:W do_epoll_ctl+0xb65
1 9.90 us 9.90 us 9.90 us rwlock:W do_exit+0x365
Fixes: d783ea8f62c4 ("perf lock contention: Simplify parse_lock_type()")
Signed-off-by: Chun-Tse Shao <ctshao@...gle.com>
---
tools/perf/builtin-lock.c | 68 ++++++++++++++++++++++++++-------------
1 file changed, 45 insertions(+), 23 deletions(-)
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index c528aff1c9d5..c1870c287580 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -1622,19 +1622,6 @@ static const char *get_type_lock_name(unsigned int flags)
return "unknown";
}
-static unsigned int get_type_flag(const char *str)
-{
- for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
- if (!strcmp(lock_type_table[i].flags_name, str))
- return lock_type_table[i].flags;
- }
- for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
- if (!strcmp(lock_type_table[i].lock_name, str))
- return lock_type_table[i].flags;
- }
- return UINT_MAX;
-}
-
static void lock_filter_finish(void)
{
zfree(&filters.types);
@@ -2356,29 +2343,64 @@ static int parse_lock_type(const struct option *opt __maybe_unused, const char *
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)) {
- unsigned int flags = get_type_flag(tok);
+ bool found = false;
- if (flags == -1U) {
- pr_err("Unknown lock flags: %s\n", tok);
- ret = -1;
- break;
+ /* `tok` is a flags name if it contains ':'. */
+ if (strchr(tok, ':')) {
+ for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
+ if (!strcmp(lock_type_table[i].flags_name, tok) &&
+ add_lock_type(lock_type_table[i].flags)) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ pr_err("Unknown lock flags name: %s\n", tok);
+ free(s);
+ return -1;
+ }
+
+ continue;
}
- if (!add_lock_type(flags)) {
- ret = -1;
- break;
+ /*
+ * Otherwise `tok` is a lock name.
+ * Single lock name could contain multiple flags.
+ */
+ /*
+ * By documentation, `percpu-rwmem` should be `pcpu-sem`.
+ * For backward compatibility, we replace `pcpu-sem` with `percpu-rwmem`.
+ */
+ if (!strcmp(tok, "pcpu-sem"))
+ tok = (char *)"percpu-rwsem";
+
+ for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
+ if (!strcmp(lock_type_table[i].lock_name, tok)) {
+ if (add_lock_type(lock_type_table[i].flags)) {
+ found = true;
+ } else {
+ free(s);
+ return -1;
+ }
+ }
+ }
+
+ if (!found) {
+ pr_err("Unknown lock name: %s\n", tok);
+ free(s);
+ return -1;
}
}
free(s);
- return ret;
+ return 0;
}
static bool add_lock_addr(unsigned long addr)
--
2.47.0.338.g60cca15819-goog
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