Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932146Ab2HFPCM (ORCPT ); Mon, 6 Aug 2012 11:02:12 -0400 Received: from acsinet15.oracle.com ([141.146.126.227]:42858 "EHLO acsinet15.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756641Ab2HFPCI (ORCPT ); Mon, 6 Aug 2012 11:02:08 -0400 Date: Mon, 6 Aug 2012 10:31:58 -0400 From: Konrad Rzeszutek Wilk To: Mel Gorman Cc: Konrad Rzeszutek Wilk , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, davem@davemloft.net, Ian Campbell , xen-devel@lists.xensource.com Subject: Re: [Xen-devel] Regression in xen-netfront on v3.6 (git commit c48a11c7ad2623b99bbd6859b0b4234e7f11176f, netvm: propagate page->pfmemalloc to skb) Message-ID: <20120806143158.GB2487@phenom.dumpdata.com> References: <20120801190227.GA13272@phenom.dumpdata.com> <20120803120414.GA10670@andromeda.dapyr.net> <20120804110355.GA17640@andromeda.dapyr.net> <20120804133105.GE29814@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120804133105.GE29814@suse.de> User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2728 Lines: 65 On Sat, Aug 04, 2012 at 02:31:05PM +0100, Mel Gorman wrote: > On Sat, Aug 04, 2012 at 07:03:55AM -0400, Konrad Rzeszutek Wilk wrote: > > On Fri, Aug 03, 2012 at 08:04:14AM -0400, Konrad Rzeszutek Wilk wrote: > > > On Wed, Aug 01, 2012 at 03:02:27PM -0400, Konrad Rzeszutek Wilk wrote: > > > > So I hadn't done a git bisection yet. But if I choose git commit: > > > > 4b24ff71108164e047cf2c95990b77651163e315 > > > > Merge tag 'for-v3.6' of git://git.infradead.org/battery-2.6 > > > > > > > > Pull battery updates from Anton Vorontsov: > > > > > > > > > > > > everything works nicely. Anything past that, so these merges: > > > > > > > > konrad@phenom:~/ssd/linux$ git log --oneline --merges 4b24ff71108164e047cf2c95990b77651163e315..linus/master > > > > 2d53492 Merge tag 'irqdomain-for-linus' of git://git.secretlab.ca/git/linux-2.6 > > > ===> ac694db Merge branch 'akpm' (Andrew's patch-bomb) > > > > > > Somewhere in there is the culprit. Hadn't done yet the full bisection > > > (was just checking out in each merge to see when it stopped working) > > > > Mel, your: > > commit c48a11c7ad2623b99bbd6859b0b4234e7f11176f > > Author: Mel Gorman > > Date: Tue Jul 31 16:44:23 2012 -0700 > > > > netvm: propagate page->pfmemalloc to skb > > > > is the culprit per git bisect. Any ideas - do the drivers need to do > > some extra processing? Here is the git bisect log > > > > The problem appears to be at drivers/net/xen-netfront.c#973 where it > calls __skb_fill_page_desc(skb, 0, NULL, 0, 0) . The driver does not > have to do extra processing as such but I did not expect NULL to be > passed in like this. Can you check if this fixes the bug please? That does it! .. snip.. > > Signed-off-by: Mel Gorman Reported-and-Tested-by: Konrad Rzeszutek Wilk > --- > include/linux/skbuff.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h > index 7632c87..8857669 100644 > --- a/include/linux/skbuff.h > +++ b/include/linux/skbuff.h > @@ -1256,7 +1256,7 @@ static inline void __skb_fill_page_desc(struct sk_buff *skb, int i, > * do not lose pfmemalloc information as the pages would not be > * allocated using __GFP_MEMALLOC. > */ > - if (page->pfmemalloc && !page->mapping) > + if (page && page->pfmemalloc && !page->mapping) > skb->pfmemalloc = true; > frag->page.p = page; > frag->page_offset = off; -- 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/