diff options
| author | Paul E. McKenney <paulmck@kernel.org> | 2025-03-14 11:26:59 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2025-05-08 16:13:26 -0700 |
| commit | d343732ddbfa15db88a628bf3284eb088efbaaf7 (patch) | |
| tree | 8375faded4c360f0318ecfdbee430a4880919cf9 /lib | |
| parent | 78bf44de47b3cec72ee8ddc14161d5b3212f25e0 (diff) | |
ratelimit: Count misses due to lock contention
The ___ratelimit() function simply returns zero ("do ratelimiting")
if the trylock fails, but does not adjust the ->missed field. This
means that the resulting dropped printk()s are dropped silently, which
could seriously confuse people trying to do console-log-based debugging.
Therefore, increment the ->missed field upon trylock failure.
Link: https://lore.kernel.org/all/fbe93a52-365e-47fe-93a4-44a44547d601@paulmck-laptop/
Link: https://lore.kernel.org/all/20250423115409.3425-1-spasswolf@web.de/
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Mateusz Guzik <mjguzik@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/ratelimit.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/lib/ratelimit.c b/lib/ratelimit.c index 18703f92d73e7..19ad3cdbd1711 100644 --- a/lib/ratelimit.c +++ b/lib/ratelimit.c @@ -44,8 +44,10 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func) * in addition to the one that will be printed by * the entity that is holding the lock already: */ - if (!raw_spin_trylock_irqsave(&rs->lock, flags)) + if (!raw_spin_trylock_irqsave(&rs->lock, flags)) { + ratelimit_state_inc_miss(rs); return 0; + } if (!rs->begin) rs->begin = jiffies; |