The patch titled rcu: increment quiescent state counter in ksoftirqd() has been added to the -mm tree. Its filename is rcu-increment-quiescent-state-counter-in-ksoftirqd.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: rcu: increment quiescent state counter in ksoftirqd() From: Eric Dumazet <dada1@xxxxxxxxxxxxx> 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@xxxxxxxxxxxxx> Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/softirq.c | 1 + 1 file changed, 1 insertion(+) diff -puN kernel/softirq.c~rcu-increment-quiescent-state-counter-in-ksoftirqd kernel/softirq.c --- a/kernel/softirq.c~rcu-increment-quiescent-state-counter-in-ksoftirqd +++ a/kernel/softirq.c @@ -648,6 +648,7 @@ 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); _ Patches currently in -mm which might be from dada1@xxxxxxxxxxxxx are linux-next.patch rcu-increment-quiescent-state-counter-in-ksoftirqd.patch softirq-introduce-statistics-for-softirq.patch proc-export-statistics-for-softirq-to-proc.patch proc-export-statistics-for-softirq-to-proc-fix.patch proc-update-document-for-proc-softirqs-and-proc-stat.patch workqueue-avoid-recursion-in-run_workqueue.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html