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| author | Paul E. McKenney <paulmck@kernel.org> | 2020-11-17 11:32:54 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2021-01-06 17:17:19 -0800 |
| commit | ea31fd9ca87399ac4e03cd6c215451fa7dc366e4 (patch) | |
| tree | 697388cc7b8d32af57a5b078965fdcc30b77dc3a /kernel/rcu | |
| parent | ae19aaafae95a5487469433e9cae4c208f8d15cd (diff) | |
| download | linux-ea31fd9ca87399ac4e03cd6c215451fa7dc366e4.tar.bz2 | |
rcutorture: Use torture_hrtimeout_jiffies() to avoid busy-waits
Because rcu_torture_writer() and rcu_torture_fakewriter() predate
hrtimers, they do timer-wheel-decoupled timed waits by using the
timer-wheel-based schedule_timeout_interruptible() functions in
conjunction with a random udelay()-based wait. This latter unnecessarily
burns CPU time, so this commit instead uses torture_hrtimeout_jiffies()
to decouple from the timer wheels without busy-waiting.
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 26 |
1 files changed, 7 insertions, 19 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 03bdf6752fe4..9414e3027a04 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1194,10 +1194,7 @@ rcu_torture_writer(void *arg) case RTWS_COND_GET: rcu_torture_writer_state = RTWS_COND_GET; gp_snap = cur_ops->get_gp_state(); - i = torture_random(&rand) % 16; - if (i != 0) - schedule_timeout_interruptible(i); - udelay(torture_random(&rand) % 1000); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); rcu_torture_writer_state = RTWS_COND_SYNC; cur_ops->cond_sync(gp_snap); rcu_torture_pipe_update(old_rp); @@ -1206,12 +1203,9 @@ rcu_torture_writer(void *arg) rcu_torture_writer_state = RTWS_POLL_GET; gp_snap = cur_ops->start_gp_poll(); rcu_torture_writer_state = RTWS_POLL_WAIT; - while (!cur_ops->poll_gp_state(gp_snap)) { - i = torture_random(&rand) % 16; - if (i != 0) - schedule_timeout_interruptible(i); - udelay(torture_random(&rand) % 1000); - } + while (!cur_ops->poll_gp_state(gp_snap)) + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); rcu_torture_pipe_update(old_rp); break; case RTWS_SYNC: @@ -1290,7 +1284,6 @@ static int rcu_torture_fakewriter(void *arg) { unsigned long gp_snap; - int i; DEFINE_TORTURE_RANDOM(rand); VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); @@ -1311,19 +1304,14 @@ rcu_torture_fakewriter(void *arg) break; case RTWS_COND_GET: gp_snap = cur_ops->get_gp_state(); - i = torture_random(&rand) % 16; - if (i != 0) - schedule_timeout_interruptible(i); - udelay(torture_random(&rand) % 1000); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, &rand); cur_ops->cond_sync(gp_snap); break; case RTWS_POLL_GET: gp_snap = cur_ops->start_gp_poll(); while (!cur_ops->poll_gp_state(gp_snap)) { - i = torture_random(&rand) % 16; - if (i != 0) - schedule_timeout_interruptible(i); - udelay(torture_random(&rand) % 1000); + torture_hrtimeout_jiffies(torture_random(&rand) % 16, + &rand); } break; case RTWS_SYNC: |