Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755253AbYGXKJb (ORCPT ); Thu, 24 Jul 2008 06:09:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751712AbYGXKJU (ORCPT ); Thu, 24 Jul 2008 06:09:20 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:46375 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751440AbYGXKJT (ORCPT ); Thu, 24 Jul 2008 06:09:19 -0400 Subject: Re: Kernel WARNING: at net/core/dev.c:1330 __netif_schedule+0x2c/0x98() From: Peter Zijlstra To: David Miller Cc: jarkao2@gmail.com, Larry.Finger@lwfinger.net, kaber@trash.net, torvalds@linux-foundation.org, akpm@linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, mingo@redhat.com, nickpiggin@yahoo.com.au, paulmck@linux.vnet.ibm.com In-Reply-To: <20080724.023210.229338550.davem@davemloft.net> References: <1216890648.7257.258.camel@twins> <20080724.022040.23129457.davem@davemloft.net> <1216891625.7257.261.camel@twins> <20080724.023210.229338550.davem@davemloft.net> Content-Type: text/plain Date: Thu, 24 Jul 2008 12:08:56 +0200 Message-Id: <1216894136.7257.266.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 909 Lines: 27 On Thu, 2008-07-24 at 02:32 -0700, David Miller wrote: > From: Peter Zijlstra > Date: Thu, 24 Jul 2008 11:27:05 +0200 > > > Well, not only lockdep, taking a very large number of locks is expensive > > as well. > > Right now it would be on the order of 16 or 32 for > real hardware. > > Much less than the scheduler currently takes on some > of my systems, so currently you are the pot calling the > kettle black. :-) One nit, and then I'll let this issue rest :-) The scheduler has a long lock dependancy chain (nr_cpu_ids rq locks), but it never takes all of them at the same time. Any one code path will at most hold two rq locks. -- 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/