Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757042AbYJVR43 (ORCPT ); Wed, 22 Oct 2008 13:56:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753454AbYJVR4U (ORCPT ); Wed, 22 Oct 2008 13:56:20 -0400 Received: from mail.fieldses.org ([66.93.2.214]:33159 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752657AbYJVR4T (ORCPT ); Wed, 22 Oct 2008 13:56:19 -0400 Date: Wed, 22 Oct 2008 13:56:17 -0400 To: linux-kernel@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: High load in 2.6.27, NFS / rpcauth_lookup_credcache()? Message-ID: <20081022175617.GA2495@fieldses.org> References: <20081022091207.GA12996@squirrel.roonstrasse.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081022091207.GA12996@squirrel.roonstrasse.net> User-Agent: Mutt/1.5.18 (2008-05-17) From: "J. Bruce Fields" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1596 Lines: 44 On Wed, Oct 22, 2008 at 11:12:08AM +0200, Max Kellermann wrote: > Hi, > > after I was able to fix http://lkml.org/lkml/2008/10/17/147, the > server which was already upgraded to 2.6.27.2 still gets very high > load. It is a web server with NFS file storage (NetApp), and while > the others in the cluster (kernel 2.6.25) have a load of 1-3, 2.6.27.2 > gets 30-50. > > I did an oprofile, with the following results (server just started, > load "only" 5-10): Well, there's only 7 patches to net/sunrpc/auth.c between 2.6.25 and today, so worst case a 'git bisect v2.6.25..v2.6.27 net/sunrpc/auth.c' might not be too bad. No particular idea why rpcauth_lookup_credcache would be a problem, though. --b. > > 87593 56.1116 (no location information) vmlinux > vmlinux rpcauth_lookup_credcache > 16037 10.2732 auth_generic.c:0 vmlinux > vmlinux generic_match > 6460 4.1382 (no location information) php4 > php4 (no symbols) > 2478 1.5874 (no location information) libc-2.7.so > libc-2.7.so (no symbols) > [...] > > We havn't configured any special authentication method. It is a NFSv3 > over UDP mount, but the kernel has NFSv4 and therefore KRB5 enabled. > > Any ideas why rpcauth_lookup_credcache() goes overboard with CPU > usage? > > Max -- 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/