On Thu, 2013-01-03 at 22:08 +0000, Ben Hutchings wrote: > On Thu, 2013-01-03 at 04:28 -0800, Eric Dumazet wrote: > > From: Eric Dumazet <eduma...@google.com> > > > > In various network workloads, __do_softirq() latencies can be up > > to 20 ms if HZ=1000, and 200 ms if HZ=100. > > > > This is because we iterate 10 times in the softirq dispatcher, > > and some actions can consume a lot of cycles. > > > > This patch changes the fallback to ksoftirqd condition to : > > > > - A time limit of 2 ms. > > - need_resched() being set on current task > [...] > > --- a/kernel/softirq.c > > +++ b/kernel/softirq.c > [...] > > -#define MAX_SOFTIRQ_RESTART 10 > > +#define MAX_SOFTIRQ_TIME min(1, (2*HZ/1000)) > [...] > > Really? Never iterate if HZ < 500? >
good catch, it should be max() -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
