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* [PATCH v6 1/3] perf lock: Fix parse_lock_type which only retrieve one lock flag
@ 2025-01-16 23:58 Chun-Tse Shao
  2025-01-16 23:58 ` [PATCH v6 2/3] perf lock: Add percpu-rwsem for type filter Chun-Tse Shao
                   ` (2 more replies)
  0 siblings, 3 replies; 4+ messages in thread
From: Chun-Tse Shao @ 2025-01-16 23:58 UTC (permalink / raw)
  To: linux-kernel
  Cc: Chun-Tse Shao, Namhyung Kim, peterz, mingo, acme, mark.rutland,
	alexander.shishkin, jolsa, irogers, adrian.hunter, kan.liang,
	nick.forrington, linux-perf-users

`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: 9.313 [sec]

         9.313976 usecs/op
           107365 ops/sec
   contended   total wait     max wait     avg wait         type   caller

         176      1.65 ms     19.43 us      9.38 us        mutex   pipe_read+0x57
          34    180.14 us     10.93 us      5.30 us        mutex   pipe_write+0x50
           7     77.48 us     16.09 us     11.07 us        mutex   do_epoll_wait+0x24d
           7     74.70 us     13.50 us     10.67 us        mutex   do_epoll_wait+0x24d
           3     35.97 us     14.44 us     11.99 us     rwlock:W   ep_done_scan+0x2d
           3     35.00 us     12.23 us     11.66 us     rwlock:W   do_epoll_wait+0x255
           2     15.88 us     11.96 us      7.94 us     rwlock:W   do_epoll_wait+0x47c
           1     15.23 us     15.23 us     15.23 us     rwlock:W   do_epoll_wait+0x4d0
           1     14.26 us     14.26 us     14.26 us     rwlock:W   ep_done_scan+0x2d
           2     14.00 us      7.99 us      7.00 us        mutex   pipe_read+0x282
           1     12.29 us     12.29 us     12.29 us     rwlock:R   ep_poll_callback+0x35
           1     12.02 us     12.02 us     12.02 us     rwlock:W   do_epoll_ctl+0xb65
           1     10.25 us     10.25 us     10.25 us     rwlock:R   ep_poll_callback+0x35
           1      7.86 us      7.86 us      7.86 us        mutex   do_epoll_ctl+0x6c1
           1      5.04 us      5.04 us      5.04 us        mutex   do_epoll_ctl+0x3d4

Fixes: d783ea8f62c4 ("perf lock contention: Simplify parse_lock_type()")
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Chun-Tse Shao <ctshao@google.com>
---
Note:
  Rebased on tmp.perf-tools-next.
  Added `mutex-spin` based on Namhyung's comment after Reviewed-by tag.

 tools/perf/builtin-lock.c | 65 ++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 25 deletions(-)

diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
index 208c482daa56..a6203c622967 100644
--- a/tools/perf/builtin-lock.c
+++ b/tools/perf/builtin-lock.c
@@ -1484,8 +1484,7 @@ static const struct {
 	{ LCB_F_PERCPU | LCB_F_WRITE,	"pcpu-sem:W",	"percpu-rwsem" },
 	{ LCB_F_MUTEX,			"mutex",	"mutex" },
 	{ LCB_F_MUTEX | LCB_F_SPIN,	"mutex",	"mutex" },
-	/* alias for get_type_flag() */
-	{ LCB_F_MUTEX | LCB_F_SPIN,	"mutex-spin",	"mutex" },
+	{ LCB_F_MUTEX | LCB_F_SPIN,	"mutex-spin",	"mutex-spin" },
 };

 static const char *get_type_str(unsigned int flags)
@@ -1510,19 +1509,6 @@ static const char *get_type_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].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].str, str))
-			return lock_type_table[i].flags;
-	}
-	return UINT_MAX;
-}
-
 static void lock_filter_finish(void)
 {
 	zfree(&filters.types);
@@ -2249,29 +2235,58 @@ 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 `str` in `lock_type_table` if it contains ':'. */
+		if (strchr(tok, ':')) {
+			for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
+				if (!strcmp(lock_type_table[i].str, 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 `name` in `lock_type_table`.
+		 * Single lock name could contain multiple flags.
+		 */
+		for (unsigned int i = 0; i < ARRAY_SIZE(lock_type_table); i++) {
+			if (!strcmp(lock_type_table[i].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)
--
2.48.0.rc2.279.g1de40edade-goog


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2025-01-18 17:59 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2025-01-16 23:58 [PATCH v6 1/3] perf lock: Fix parse_lock_type which only retrieve one lock flag Chun-Tse Shao
2025-01-16 23:58 ` [PATCH v6 2/3] perf lock: Add percpu-rwsem for type filter Chun-Tse Shao
2025-01-16 23:58 ` [PATCH v6 3/3] perf lock: Rename fields in lock_type_table Chun-Tse Shao
2025-01-18 17:59 ` [PATCH v6 1/3] perf lock: Fix parse_lock_type which only retrieve one lock flag Namhyung Kim

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