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? Ben. -- Ben Hutchings, Staff Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked. -- 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/
