From ee042be16cb455116d0fe99b77c6bc8baf87c8c6 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Tue, 22 Mar 2022 11:57:09 -0700 Subject: locking: Apply contention tracepoints in the slow path Adding the lock contention tracepoints in various lock function slow paths. Note that each arch can define spinlock differently, I only added it only to the generic qspinlock for now. Signed-off-by: Namhyung Kim Signed-off-by: Peter Zijlstra (Intel) Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lkml.kernel.org/r/20220322185709.141236-3-namhyung@kernel.org --- kernel/locking/rwsem.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'kernel/locking/rwsem.c') diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 16b532bb5b92..9d1db4a54d34 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -27,6 +27,7 @@ #include #include #include +#include #ifndef CONFIG_PREEMPT_RT #include "lock_events.h" @@ -1056,6 +1057,8 @@ queue: if (!wake_q_empty(&wake_q)) wake_up_q(&wake_q); + trace_contention_begin(sem, LCB_F_READ); + /* wait to be given the lock */ for (;;) { set_current_state(state); @@ -1077,12 +1080,14 @@ queue: __set_current_state(TASK_RUNNING); lockevent_inc(rwsem_rlock); + trace_contention_end(sem, 0); return sem; out_nolock: rwsem_del_wake_waiter(sem, &waiter, &wake_q); __set_current_state(TASK_RUNNING); lockevent_inc(rwsem_rlock_fail); + trace_contention_end(sem, -EINTR); return ERR_PTR(-EINTR); } @@ -1132,6 +1137,8 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state) /* wait until we successfully acquire the lock */ set_current_state(state); + trace_contention_begin(sem, LCB_F_WRITE); + for (;;) { if (rwsem_try_write_lock(sem, &waiter)) { /* rwsem_try_write_lock() implies ACQUIRE on success */ @@ -1171,6 +1178,7 @@ trylock_again: __set_current_state(TASK_RUNNING); raw_spin_unlock_irq(&sem->wait_lock); lockevent_inc(rwsem_wlock); + trace_contention_end(sem, 0); return sem; out_nolock: @@ -1178,6 +1186,7 @@ out_nolock: raw_spin_lock_irq(&sem->wait_lock); rwsem_del_wake_waiter(sem, &waiter, &wake_q); lockevent_inc(rwsem_wlock_fail); + trace_contention_end(sem, -EINTR); return ERR_PTR(-EINTR); } -- cgit