Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759250AbXEUH70 (ORCPT ); Mon, 21 May 2007 03:59:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755016AbXEUH7S (ORCPT ); Mon, 21 May 2007 03:59:18 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:48847 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755072AbXEUH7R (ORCPT ); Mon, 21 May 2007 03:59:17 -0400 Date: Mon, 21 May 2007 09:58:24 +0200 From: Ingo Molnar To: Anant Nitya Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Thomas Gleixner , "David S. Miller" Subject: Re: bad networking related lag in v2.6.22-rc2 Message-ID: <20070521075824.GA11198@elte.hu> References: <20070517174533.GA538@elte.hu> <200705180317.06014.kernel@prachanda.hub> <20070518102607.GA23151@elte.hu> <200705200246.22444.kernel@prachanda.hub> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200705200246.22444.kernel@prachanda.hub> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -0.7 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-0.7 required=5.9 tests=BAYES_00,INFO_TLD autolearn=no SpamAssassin version=3.1.7 1.3 INFO_TLD URI: Contains an URL in the INFO top-level domain -2.0 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1805 Lines: 43 * Anant Nitya wrote: > Please ignore my last report about lag problem while using CFS-v13, it > is working perfectly fine with 2.6.21.1 and the lag I used to see in > v12 is not there with v13 anymore. After digging in a bit I found that > problem is only occurring in 2.6.22-rc1 and it get fired by network > usage while transmitting data upstream. I don't have any evidence that > CFS is involved in lag problem since 2.6.22-rc1 with stock scheduler > is also having same lag problem and it seems directly proportional > with upstream speed while downstream doesn't shows any misbehavior { > at lower upstream speed lag is less but with higher upstream speed > system starts crawling and system load hitting to 70/75}. Lets see how > 2.6.22-rc2 is doing. ok, i got your -rc2 debug numbers (off-list), and it doesnt look pretty: before-lag: sleep_max : 259502076 block_max : 27690921 wait_max : 16381558 after-lag: sleep_max : 584186160 block_max : 261780071 wait_max : 881255577 ouch! a nearly 1 second delay got observed by the scheduler - something is really killing your system! what does 'top' show during an upload? Is any system related task out of whack? Could you try to get a readprofile or an oprofile output from the kernel, so that we can see what is slowing it down so much? It could be something networking related in v2.6.22-rc2. Ingo - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/