6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chun-Tse Shao ctshao@google.com
[ Upstream commit 1be9264158ef4818393e5d8144887a1a5d3cc480 ]
`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
[namhyung: Add a comment and rename to 'mutex:spin' for consistency
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 Cc: nick.forrington@arm.com Link: https://lore.kernel.org/r/20250116235838.2769691-1-ctshao@google.com Signed-off-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/perf/builtin-lock.c | 66 ++++++++++++++++++++++++--------------- 1 file changed, 41 insertions(+), 25 deletions(-)
diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c index fcb32c58bee7e..bd24ed0af208a 100644 --- a/tools/perf/builtin-lock.c +++ b/tools/perf/builtin-lock.c @@ -1591,8 +1591,8 @@ 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" }, + /* alias for optimistic spinning only */ + { LCB_F_MUTEX | LCB_F_SPIN, "mutex:spin", "mutex-spin" }, };
static const char *get_type_str(unsigned int flags) @@ -1617,19 +1617,6 @@ 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); @@ -2321,29 +2308,58 @@ 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)