From: David Miller <davem@davemloft.net>
To: eric.dumazet@gmail.com
Cc: yanmin_zhang@linux.intel.com, cl@linux-foundation.org,
penberg@cs.helsinki.fi, netdev@vger.kernel.org, tj@kernel.org,
alex.shi@intel.com, linux-kernel@vger.kernel.org,
ling.ma@intel.com, tim.c.chen@intel.com,
akpm@linux-foundation.org
Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e
Date: Thu, 08 Apr 2010 00:05:57 -0700 (PDT) [thread overview]
Message-ID: <20100408.000557.180546976.davem@davemloft.net> (raw)
In-Reply-To: <1270710019.2215.4.camel@edumazet-laptop>
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Thu, 08 Apr 2010 09:00:19 +0200
> If run individually, the tests results are more what we would expect
> (slow), but if machine runs the two set of process concurrently, each
> group runs much faster...
BTW, I just discovered (thanks to the function graph tracer, woo hoo!)
that loopback TCP packets get fully checksum validated on receive.
I'm trying to figure out why skb->ip_summed ends up being
CHECKSUM_NONE in tcp_v4_rcv() even though it gets set to
CHECKSUM_PARTIAL in tcp_sendmsg().
I wonder how much this accounts for some of the hackbench
oddities... and other regressions in loopback tests we've seen.
:-)
Just FYI...
next prev parent reply other threads:[~2010-04-08 7:05 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1269506457.4513.141.camel@alexs-hp.sh.intel.com>
[not found] ` <alpine.DEB.2.00.1003250942080.2670@router.home>
[not found] ` <1269570902.9614.92.camel@alexs-hp.sh.intel.com>
[not found] ` <1270114166.2078.107.camel@ymzhang.sh.intel.com>
[not found] ` <alpine.DEB.2.00.1004011050340.16531@router.home>
[not found] ` <1270195589.2078.116.camel@ymzhang.sh.intel.com>
[not found] ` <alpine.DEB.2.00.1004050853300.23149@router.home>
[not found] ` <i2z84144f021004051030k7ff5190cyc083aa12c552dfac@mail.gmail.com>
[not found] ` <4BBA8DF9.8010409@kernel.org>
[not found] ` <1270542497.2078.123.camel@ymzhang.sh.intel.com>
[not found] ` <alpine.DEB.2.00.1004061033330.18750@router.home>
[not found] ` <alpine.DEB.2.00.1004061552500.19151@router.home>
2010-04-06 22:10 ` hackbench regression due to commit 9dfc6e68bfe6e Eric Dumazet
2010-04-07 2:34 ` Zhang, Yanmin
2010-04-07 6:39 ` Eric Dumazet
2010-04-07 9:07 ` Zhang, Yanmin
2010-04-07 9:20 ` Eric Dumazet
2010-04-07 10:47 ` Pekka Enberg
2010-04-07 16:30 ` Christoph Lameter
2010-04-07 16:43 ` Christoph Lameter
2010-04-07 16:49 ` Pekka Enberg
2010-04-07 16:52 ` Pekka Enberg
2010-04-07 18:20 ` Christoph Lameter
2010-04-07 18:25 ` Pekka Enberg
2010-04-07 19:30 ` Christoph Lameter
2010-04-07 18:38 ` Eric Dumazet
2010-04-08 1:05 ` Zhang, Yanmin
2010-04-08 4:59 ` Eric Dumazet
2010-04-08 5:39 ` Eric Dumazet
2010-04-08 7:00 ` Eric Dumazet
2010-04-08 7:05 ` David Miller [this message]
2010-04-08 7:20 ` David Miller
2010-04-08 7:25 ` Eric Dumazet
2010-04-08 7:54 ` Zhang, Yanmin
2010-04-08 7:54 ` Eric Dumazet
2010-04-08 8:09 ` Eric Dumazet
2010-04-08 15:34 ` Christoph Lameter
2010-04-08 15:52 ` Eric Dumazet
2010-04-07 18:18 ` Christoph Lameter
2010-04-08 7:18 ` Zhang, Yanmin
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