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| author | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-07-01 22:26:57 +0400 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2014-09-08 03:27:20 +0400 |
| commit | bde6c3aa993066acb0d6ce32ecabe03b9d5df92d (patch) | |
| tree | 09ec78a9cfa751ce36288c32c4e5112f34af8582 /kernel/rcu/rcutorture.c | |
| parent | 8315f42295d2667a7f942f154b73a86fd7cb2227 (diff) | |
| download | linux-bde6c3aa993066acb0d6ce32ecabe03b9d5df92d.tar.xz | |
rcu: Provide cond_resched_rcu_qs() to force quiescent states in long loops
RCU-tasks requires the occasional voluntary context switch
from CPU-bound in-kernel tasks. In some cases, this requires
instrumenting cond_resched(). However, there is some reluctance
to countenance unconditionally instrumenting cond_resched() (see
http://lwn.net/Articles/603252/), so this commit creates a separate
cond_resched_rcu_qs() that may be used in place of cond_resched() in
locations prone to long-duration in-kernel looping.
This commit currently instruments only RCU-tasks. Future possibilities
include also instrumenting RCU, RCU-bh, and RCU-sched in order to reduce
IPI usage.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/rcutorture.c')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 948a7693748e..178716713e11 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -667,7 +667,7 @@ static int rcu_torture_boost(void *arg) } call_rcu_time = jiffies; } - cond_resched(); + cond_resched_rcu_qs(); stutter_wait("rcu_torture_boost"); if (torture_must_stop()) goto checkwait; @@ -1019,7 +1019,7 @@ rcu_torture_reader(void *arg) __this_cpu_inc(rcu_torture_batch[completed]); preempt_enable(); cur_ops->readunlock(idx); - cond_resched(); + cond_resched_rcu_qs(); stutter_wait("rcu_torture_reader"); } while (!torture_must_stop()); if (irqreader && cur_ops->irq_capable) { |