From patchwork Fri Aug 16 20:18:14 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Weiner X-Patchwork-Id: 2845762 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 41354BF546 for ; Fri, 16 Aug 2013 20:22:35 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 5B4502020A for ; Fri, 16 Aug 2013 20:22:34 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 56DFC201B5 for ; Fri, 16 Aug 2013 20:22:33 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VAQXR-0004Bw-J5; Fri, 16 Aug 2013 20:22:25 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VAQXM-0002ZF-5F; Fri, 16 Aug 2013 20:22:20 +0000 Received: from zene.cmpxchg.org ([2a01:238:4224:fa00:ca1f:9ef3:caee:a2bd]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VAQXI-0002Yb-E0 for linux-arm-kernel@lists.infradead.org; Fri, 16 Aug 2013 20:22:17 +0000 Received: from ool-4578dd68.dyn.optonline.net ([69.120.221.104] helo=phnom.home.cmpxchg.org) by zene.cmpxchg.org with esmtpsa (TLSv1:AES128-SHA:128) (Exim 4.76) (envelope-from ) id 1VAQTa-0000DK-Ve; Fri, 16 Aug 2013 20:18:27 +0000 Date: Fri, 16 Aug 2013 16:18:14 -0400 From: Johannes Weiner To: Kevin Hilman Subject: Re: [patch v2 3/3] mm: page_alloc: fair zone allocator policy Message-ID: <20130816201814.GA26409@cmpxchg.org> References: <1375457846-21521-1-git-send-email-hannes@cmpxchg.org> <1375457846-21521-4-git-send-email-hannes@cmpxchg.org> <20130807145828.GQ2296@suse.de> <20130807153743.GH715@cmpxchg.org> <20130808041623.GL1845@cmpxchg.org> <87haepblo2.fsf@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <87haepblo2.fsf@kernel.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130816_162216_883825_6AA9C4A0 X-CRM114-Status: GOOD ( 20.96 ) X-Spam-Score: -4.6 (----) Cc: Andrea Arcangeli , Rik van Riel , Zlatko Calusic , Stephen Warren , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Minchan Kim , Mel Gorman , Olof Johansson , Andrew Morton , "sfr@canb.auug.org.au linux-arm-kernel" X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Hi Kevin, On Fri, Aug 16, 2013 at 10:17:01AM -0700, Kevin Hilman wrote: > Johannes Weiner writes: > > On Wed, Aug 07, 2013 at 11:37:43AM -0400, Johannes Weiner wrote: > > Subject: [patch] mm: page_alloc: use vmstats for fair zone allocation batching > > > > Avoid dirtying the same cache line with every single page allocation > > by making the fair per-zone allocation batch a vmstat item, which will > > turn it into batched percpu counters on SMP. > > > > Signed-off-by: Johannes Weiner > > I bisected several boot failures on various ARM platform in > next-20130816 down to this patch (commit 67131f9837 in linux-next.) > > Simply reverting it got things booting again on top of -next. Example > boot crash below. Thanks for the bisect and report! I deref the percpu pointers before initializing them properly. It didn't trigger on x86 because the percpu offset added to the pointer is big enough so that it does not fall into PFN 0, but it probably ended up corrupting something... Could you try this patch on top of linux-next instead of the revert? Thanks, Johannes Tested-by: Stephen Warren Tested-by: Kevin Hilman --- From: Johannes Weiner Subject: [patch] mm: page_alloc: use vmstats for fair zone allocation batching fix Initialize the per-cpu counters before modifying them. Otherwise: [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 3.11.0-rc5-next-20130816 (khilman@paris) (gcc version 4.7.2 (Ubuntu/Linaro 4.7.2-1ubuntu1) ) #30 SMP Fri Aug 16 09:47:32 PDT 2013 [ 0.000000] CPU: ARMv7 Processor [413fc082] revision 2 (ARMv7), cr=10c53c7d [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] Machine: Generic AM33XX (Flattened Device Tree), model: TI AM335x BeagleBone [ 0.000000] bootconsole [earlycon0] enabled [ 0.000000] Memory policy: ECC disabled, Data cache writeback [ 0.000000] On node 0 totalpages: 130816 [ 0.000000] free_area_init_node: node 0, pgdat c081d400, node_mem_map c12fc000 [ 0.000000] Normal zone: 1024 pages used for memmap [ 0.000000] Normal zone: 0 pages reserved [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000026 [ 0.000000] pgd = c0004000 [ 0.000000] [00000026] *pgd=00000000 [ 0.000000] Internal error: Oops: 5 [#1] SMP ARM [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 3.11.0-rc5-next-20130816 #30 [ 0.000000] task: c0793c70 ti: c0788000 task.ti: c0788000 [ 0.000000] PC is at __mod_zone_page_state+0x2c/0xb4 [ 0.000000] LR is at mod_zone_page_state+0x2c/0x4c Reported-by: Kevin Hilman Signed-off-by: Johannes Weiner --- mm/page_alloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6a95d39..b9e8f2f 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4826,11 +4826,11 @@ static void __paginginit free_area_init_core(struct pglist_data *pgdat, spin_lock_init(&zone->lru_lock); zone_seqlock_init(zone); zone->zone_pgdat = pgdat; + zone_pcp_init(zone); /* For bootup, initialized properly in watermark setup */ mod_zone_page_state(zone, NR_ALLOC_BATCH, zone->managed_pages); - zone_pcp_init(zone); lruvec_init(&zone->lruvec); if (!size) continue;