From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH v2 net-next] softirq: reduce latencies
Date: Fri, 04 Jan 2013 13:49:10 -0800 (PST)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 03 Jan 2013 23:49:40 -0800

> From: Eric Dumazet <edumazet@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
> 
> When one of this condition is met, we wakeup ksoftirqd for further
> softirq processing if we still have pending softirqs.
 ...
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Acked-by: David S. Miller <davem@davemloft.net>