From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f198.google.com (mail-ig0-f198.google.com [209.85.213.198]) by kanga.kvack.org (Postfix) with ESMTP id 2B1806B025E for ; Mon, 30 May 2016 13:37:41 -0400 (EDT) Received: by mail-ig0-f198.google.com with SMTP id lp2so121871408igb.3 for ; Mon, 30 May 2016 10:37:41 -0700 (PDT) Received: from mail-it0-x242.google.com (mail-it0-x242.google.com. [2607:f8b0:4001:c0b::242]) by mx.google.com with ESMTPS id j9si39819228iof.177.2016.05.30.10.37.40 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 May 2016 10:37:40 -0700 (PDT) Received: by mail-it0-x242.google.com with SMTP id z123so6930958itg.2 for ; Mon, 30 May 2016 10:37:40 -0700 (PDT) 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 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 Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Linux Kernel Mailing List , Linux MM , linux-m68k 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 -- 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