diff options
| author | Eric Dumazet <dada1@cosmosbay.com> | 2009-03-04 12:11:56 -0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-03-04 22:08:45 +0100 |
| commit | 64ca5ab913f1594ef316556e65f5eae63ff50cee (patch) | |
| tree | 44cecee89609fbec9e4d7ed853b0eaf5c3782fc3 /kernel/softirq.c | |
| parent | 559595a985e106d2fa9f0c79b7f5805453fed593 (diff) | |
| download | lwn-64ca5ab913f1594ef316556e65f5eae63ff50cee.tar.gz lwn-64ca5ab913f1594ef316556e65f5eae63ff50cee.zip | |
rcu: increment quiescent state counter in ksoftirqd()
If a machine is flooded by network frames, a cpu can loop
100% of its time inside ksoftirqd() without calling schedule().
This can delay RCU grace period to insane values.
Adding rcu_qsctr_inc() call in ksoftirqd() solves this problem.
Paul: "This regression was a result of the recent change from
"schedule()" to "cond_resched()", which got rid of that quiescent
state in the common case where a reschedule is not needed".
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/softirq.c')
| -rw-r--r-- | kernel/softirq.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/softirq.c b/kernel/softirq.c index bdbe9de9cd8d..9041ea7948fe 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -626,6 +626,7 @@ static int ksoftirqd(void * __bind_cpu) preempt_enable_no_resched(); cond_resched(); preempt_disable(); + rcu_qsctr_inc((long)__bind_cpu); } preempt_enable(); set_current_state(TASK_INTERRUPTIBLE); |