From: Eric Dumazet <eric.dumazet@gmail.com>
To: 叶雨飞 <sunyucong@gmail.com>
Cc: netdev <netdev@vger.kernel.org>
Subject: Re: ksoftirqd 100% after disabling IPv4 route cache on high pps.
Date: Wed, 05 Dec 2012 15:48:51 -0800 [thread overview]
Message-ID: <1354751331.31222.295.camel@edumazet-glaptop> (raw)
In-Reply-To: <CAJygYd187B1305puZwdiK6kfP=LPPvyX_rGJn9g2azaRs4p8ZA@mail.gmail.com>
On Wed, 2012-12-05 at 13:22 -0800, 叶雨飞 wrote:
> Hi Eric,
>
> After disabling the route cache, I found a forwarding performance
> problem (inevitable ?). Basically the kernel couldn't keep up under
> about 100k pps and ksoftirqd is dominating the CPU. This problem went
> away right away if I do
>
> echo 1 > rt_cache_rebuild_count
>
> and comes back as soon as i do echo -1 > rt_cache_rebuild_count.
>
> I then tried to use RPS/RFS to share the load on to mulitple cpus
> (since ksoftirqd is only using 1 core, clearly). but that has little
> effect.
>
> Is there some tweaks/patches you recommend?
Yes, upgrade your kernel to 3.6 or 3.7, this problem has been solved for
good. No more IP route cache and good performance.
next prev parent reply other threads:[~2012-12-05 23:48 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-05 21:22 ksoftirqd 100% after disabling IPv4 route cache on high pps 叶雨飞
2012-12-05 23:48 ` Eric Dumazet [this message]
[not found] ` <CAJygYd0-tLRJ6wnzKhXEL7W8hJJzKr=YST_cQxyvHvOKprcHjQ@mail.gmail.com>
2012-12-06 0:34 ` 叶雨飞
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