From: ebiederm@xmission.com (Eric W. Biederman)
To: David Miller <davem@davemloft.net>
Cc: fengguang.wu@intel.com, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: -27% netperf TCP_STREAM regression by "tcp_memcontrol: Kill struct tcp_memcontrol"
Date: Tue, 22 Oct 2013 21:38:10 -0700 [thread overview]
Message-ID: <87k3h461ql.fsf@tw-ebiederman.twitter.com> (raw)
In-Reply-To: <20131022.180023.1141845387743361648.davem@davemloft.net> (David Miller's message of "Tue, 22 Oct 2013 18:00:23 -0400 (EDT)")
David Miller <davem@davemloft.net> writes:
> From: fengguang.wu@intel.com
> Date: Tue, 22 Oct 2013 22:41:29 +0100
>
>> We noticed big netperf throughput regressions
>>
>> a4fe34bf902b8f709c63 2e685cad57906e19add7
>> ------------------------ ------------------------
>> 707.40 -40.7% 419.60 lkp-nex04/micro/netperf/120s-200%-TCP_STREAM
>> 2775.60 -23.7% 2116.40 lkp-sb03/micro/netperf/120s-200%-TCP_STREAM
>> 3483.00 -27.2% 2536.00 TOTAL netperf.Throughput_Mbps
>>
>> and bisected it to
>>
>> commit 2e685cad57906e19add7189b5ff49dfb6aaa21d3
>> Author: Eric W. Biederman <ebiederm@xmission.com>
>> Date: Sat Oct 19 16:26:19 2013 -0700
>>
>> tcp_memcontrol: Kill struct tcp_memcontrol
>
> Eric please look into this, I'd rather have a fix to apply than revert your
> work.
Will do I expect some ordering changed, and that changed the cache line
behavior.
If I can't find anything we can revert this one particular patch without
affecting anything else, but it would be nice to keep the data structure
smaller.
Fengguag what would I need to do to reproduce this?
Eric
next prev parent reply other threads:[~2013-10-23 4:42 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-22 21:41 -27% netperf TCP_STREAM regression by "tcp_memcontrol: Kill struct tcp_memcontrol" fengguang.wu
2013-10-22 22:00 ` David Miller
2013-10-23 4:38 ` Eric W. Biederman [this message]
2013-10-23 6:10 ` Fengguang Wu
2013-10-23 9:43 ` Eric W. Biederman
2013-10-23 11:46 ` Fengguang Wu
2013-10-23 12:25 ` Christoph Paasch
2013-10-23 13:02 ` Eric Dumazet
2013-10-23 19:55 ` [PATCH] Fix: Dereference pointer-value of sk_prot->memory_pressure Eric W. Biederman
2013-10-23 20:15 ` David Miller
2013-10-23 19:58 ` Eric W. Biederman
2013-10-23 22:07 ` -27% netperf TCP_STREAM regression by "tcp_memcontrol: Kill struct tcp_memcontrol" Fengguang Wu
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