From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161764AbcE3Rhn (ORCPT ); Mon, 30 May 2016 13:37:43 -0400 Received: from mail-it0-f66.google.com ([209.85.214.66]:34283 "EHLO mail-it0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933000AbcE3Rhl (ORCPT ); Mon, 30 May 2016 13:37:41 -0400 MIME-Version: 1.0 In-Reply-To: <20160530155644.GP2527@techsingularity.net> References: <20160530155644.GP2527@techsingularity.net> Date: Mon, 30 May 2016 19:37:39 +0200 X-Google-Sender-Auth: FT96KkLKDKB9fPoXDIRPYwtSmGI Message-ID: Subject: Re: BUG: scheduling while atomic: cron/668/0x10c9a0c0 (was: Re: mm, page_alloc: avoid looking up the first zone in a zonelist twice) From: Geert Uytterhoeven To: Mel Gorman Cc: Andrew Morton , Linux Kernel Mailing List , Linux MM , linux-m68k Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mel, On Mon, May 30, 2016 at 5:56 PM, Mel Gorman wrote: > On Mon, May 30, 2016 at 03:13:40PM +0200, Geert Uytterhoeven wrote: >> > The benefit is negligible and the results are within the noise but each >> > cycle counts. >> > >> > Signed-off-by: Mel Gorman >> > Cc: Vlastimil Babka >> > Cc: Jesper Dangaard Brouer >> > Signed-off-by: Andrew Morton >> > Signed-off-by: Linus Torvalds >> >> About one week ago, I started seeing an obscure intermittent crash during >> system shutdown on m68k/ARAnyM using atari_defconfig. >> The crash isn't 100% reproducible, but it happens during ca. 1 out of 5 >> shutdowns. >> >> I finally managed to bisect it to the above commit. >> I did verify that the parent commit didn't crash after 60 tries. >> Unfortunately I couldn't revert the offending commit on top of v4.7-rc1, due to >> conflicting changes. >> >> Do you have any idea what's going wrong? > > There isn't anything obvious from the crash log you showed but can you > try the following just in case? > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index dba8cfd0b2d6..f2c1e47adc11 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3232,6 +3232,9 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, > * allocations are system rather than user orientated > */ > ac->zonelist = node_zonelist(numa_node_id(), gfp_mask); > + ac->preferred_zoneref = first_zones_zonelist(ac->zonelist, > + ac->high_zoneidx, ac->nodemask); > + ac->classzone_idx = zonelist_zone_idx(ac->preferred_zoneref); > page = get_page_from_freelist(gfp_mask, order, > ALLOC_NO_WATERMARKS, ac); > if (page) Thanks, but unfortunately it doesn't help. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds