From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758554Ab0DHH0A (ORCPT ); Thu, 8 Apr 2010 03:26:00 -0400 Received: from mail-bw0-f209.google.com ([209.85.218.209]:34062 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758509Ab0DHHZ4 (ORCPT ); Thu, 8 Apr 2010 03:25:56 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=n8NROewiopq0szTwZHJ8+EpNNL4vzV7cPaMARE+4uIdK2oxUheuSIdc4v6Kv3Iut52 w4GK8eGeuFiGopz4RN2Ntg7rh6q57nj68GoUshlMNA6hMa5dIbL6ciRT7DfAiVDQFwQK P/GKTIHAVyKfrF/KdBPT73rrbLZA17uOtBQpw= Subject: Re: hackbench regression due to commit 9dfc6e68bfe6e From: Eric Dumazet To: David Miller 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 In-Reply-To: <20100408.000557.180546976.davem@davemloft.net> References: <1270702774.8141.49.camel@edumazet-laptop> <1270705153.8141.58.camel@edumazet-laptop> <1270710019.2215.4.camel@edumazet-laptop> <20100408.000557.180546976.davem@davemloft.net> Content-Type: text/plain; charset="UTF-8" Date: Thu, 08 Apr 2010 09:25:51 +0200 Message-ID: <1270711551.2215.5.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le jeudi 08 avril 2010 à 00:05 -0700, David Miller a écrit : > From: Eric Dumazet > 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... Thanks ! But hackbench is a af_unix benchmark, so loopback stuff is not used that much :)