From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail143.messagelabs.com (mail143.messagelabs.com [216.82.254.35]) by kanga.kvack.org (Postfix) with ESMTP id 380486B004F for ; Tue, 16 Jun 2009 10:21:38 -0400 (EDT) Date: Tue, 16 Jun 2009 16:22:14 +0200 From: Nick Piggin Subject: Re: 2.6.29.4: softlockup at find_get_page() et al Message-ID: <20090616142214.GB18444@wotan.suse.de> References: <20090616110051.GA4864@x200.localdomain> <20090616130833.GA27925@wotan.suse.de> <20090616131454.GA6168@x200.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090616131454.GA6168@x200.localdomain> Sender: owner-linux-mm@kvack.org To: Alexey Dobriyan Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Tue, Jun 16, 2009 at 05:14:54PM +0400, Alexey Dobriyan wrote: > On Tue, Jun 16, 2009 at 03:08:33PM +0200, Nick Piggin wrote: > > Thanks. Is it rebooted? It would be interesting to know what other > > CPUs are doing (and even what other tasks are doing) if it is > > still up. > > It was rebooted, sorry. Thanks. It is hard to know where it is looping, but I see a put_page in there which seems to suggest it reached at least the "Has the page moved" test. But if the stack trace is 100% accurate, then it seems like it has hit the "Has the page been truncated" part of find_lock_page. And it is an ext2 dir page. And these pages should not get truncated unless rmdir. But we can't be in rmdir I think because we are doing a mkdir. It would seem like the page is still in the pagecache, but ->mapping is wrong. But actually that is strange because we should have a new inode here, so find_get_page should not even find a page in find_or_create_page. There should be no way for a racing thread to add a page there either. I would almost have to suspect hardware or software error causing random memory scribble. I would definitely be very interested if you can reproduce (I suspect it won't be reproducable though). Thanks, Nick -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org