netdev - Re: Performance regression on kernels 3.10 and newer

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Date:	Thu, 14 Aug 2014 12:59:18 -0700
From:	Rick Jones <rick.jones2@...com>
To:	Eric Dumazet <eric.dumazet@...il.com>,
	Alexander Duyck <alexander.h.duyck@...el.com>
CC:	David Miller <davem@...emloft.net>, netdev <netdev@...r.kernel.org>
Subject: Re: Performance regression on kernels 3.10 and newer

On 08/14/2014 11:46 AM, Eric Dumazet wrote:

> I believe you answered your own question : prequeue mode does not work
> very well when one host has hundred of active TCP flows to one other.
>
> In real life, applications do not use prequeue, because nobody wants one
> thread per flow.
>
> Each socket has its own dst now route cache was removed, but if your
> netperf migrates cpu (and NUMA node), we do not detect the dst should be
> re-created onto a different NUMA node.

Presumably, the -T $i,$j option in Alex's netperf command lines will 
have bound netperf and netserver to a specific CPU where they will have 
remained.

rick jones
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