Return-Path: linux-nfs-owner@vger.kernel.org Received: from mout.gmx.net ([212.227.15.15]:51718 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752128Ab3JSS1q (ORCPT ); Sat, 19 Oct 2013 14:27:46 -0400 Received: from [192.168.178.60] ([84.173.16.34]) by mail.gmx.com (mrgmx001) with ESMTPSA (Nemesis) id 0M5dMm-1VvbM82pL6-00xZE0 for ; Sat, 19 Oct 2013 20:27:44 +0200 Message-ID: <5262CF20.20301@gmx.de> Date: Sat, 19 Oct 2013 20:27:44 +0200 From: Helge Deller MIME-Version: 1.0 To: "Myklebust, Trond" CC: Linux Kernel Development , NFS list , linux-parisc Subject: Re: 3.12-rcX - NFS regression - kswapd0 / kswapd1 stays using 100% CPU? References: <52604BA9.20104@gmx.de> <1382044045.3216.44.camel@leira.trondhjem.org> <52618B5F.4000508@gmx.de> <1382124981.20461.4.camel@leira.trondhjem.org> <5261940A.4090101@gmx.de> <1382127133.20461.9.camel@leira.trondhjem.org> In-Reply-To: <1382127133.20461.9.camel@leira.trondhjem.org> Content-Type: text/plain; charset=UTF-7 Sender: linux-nfs-owner@vger.kernel.org List-ID: On 10/18/2013 10:12 PM, Myklebust, Trond wrote: > On Fri, 2013-10-18 at 22:03 +0200, Helge Deller wrote: >> On 10/18/2013 09:36 PM, Myklebust, Trond wrote: >>> Also, could you please try a sysRQ-t the next time it happens, so that >>> we can get a trace of where the mount program is hanging. Knowing that >>> the mount is stuck in "__schedule()" is not really interesting unless we >>> know from where that was called. >> >> Actually, the machine was still running in this state. >> Here is sysrq-t: >> [112009.084000] mount S 00000000401040c0 0 25331 1 0x00000010 >> [112009.084000] Backtrace: >> [112009.084000] [<0000000040113a68>] __schedule >> [112009.232000] >> [112009.232000] mount.nfs D 00000000401040c0 0 25332 25331 0x00000010 >> [112009.232000] Backtrace: >> [112009.232000] [<0000000040113a68>] __schedule > > That makes no sense unless sysrq-t works differently on parisc than on > other platforms. I'd expect the backtrace to at least include a system > call. Parisc experts? sysrq-t doesn't work differently on parisc. For other processes I do get a backtrace like the one on x86_64. That's the main reason why I asked for ideas here on the list. I do see the stuck process, but don't see any indications where it comes from. Helge