From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f182.google.com (mail-ob0-f182.google.com [209.85.214.182]) by kanga.kvack.org (Postfix) with ESMTP id 10A8A828E1 for ; Mon, 8 Feb 2016 06:35:48 -0500 (EST) Received: by mail-ob0-f182.google.com with SMTP id is5so147670504obc.0 for ; Mon, 08 Feb 2016 03:35:48 -0800 (PST) Received: from e37.co.us.ibm.com (e37.co.us.ibm.com. [32.97.110.158]) by mx.google.com with ESMTPS id ny9si15820491obc.30.2016.02.08.03.35.47 for (version=TLS1 cipher=AES128-SHA bits=128/128); Mon, 08 Feb 2016 03:35:47 -0800 (PST) Received: from localhost by e37.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 8 Feb 2016 04:35:46 -0700 Received: from b01cxnp22035.gho.pok.ibm.com (b01cxnp22035.gho.pok.ibm.com [9.57.198.25]) by d03dlp01.boulder.ibm.com (Postfix) with ESMTP id 6C5511FF0045 for ; Mon, 8 Feb 2016 04:23:41 -0700 (MST) Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u18BZV386815818 for ; Mon, 8 Feb 2016 11:35:31 GMT Received: from d01av02.pok.ibm.com (localhost [127.0.0.1]) by d01av02.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u18BZTOb017434 for ; Mon, 8 Feb 2016 06:35:30 -0500 Message-ID: <56B87E32.4050003@linux.vnet.ibm.com> Date: Mon, 08 Feb 2016 17:08:26 +0530 From: Raghavendra K T MIME-Version: 1.0 Subject: Re: [tip:sched/urgent] sched: Fix crash in sched_init_numa() References: <1452884483-11676-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: tglx@linutronix.de, mingo@kernel.org, linux-mm@kvack.org, mpe@ellerman.id.au, hpa@zytor.com, nikunj@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, peterz@infradead.org, vdavydov@parallels.com, gkurz@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, raghavendra.kt@linux.vnet.ibm.com, jstancek@redhat.com, benh@kernel.crashing.org, anton@samba.org, grant.likely@linaro.org, paulus@samba.org, Greg Kroah-Hartman , stable@vger.kernel.org Cc: tip-bot for Raghavendra K T , linux-tip-commits@vger.kernel.org On 01/19/2016 07:08 PM, tip-bot for Raghavendra K T wrote: > Commit-ID: 9c03ee147193645be4c186d3688232fa438c57c7 > Gitweb: http://git.kernel.org/tip/9c03ee147193645be4c186d3688232fa438c57c7 > Author: Raghavendra K T > AuthorDate: Sat, 16 Jan 2016 00:31:23 +0530 > Committer: Ingo Molnar > CommitDate: Tue, 19 Jan 2016 08:42:20 +0100 > > sched: Fix crash in sched_init_numa() > > The following PowerPC commit: > > c118baf80256 ("arch/powerpc/mm/numa.c: do not allocate bootmem memory for non existing nodes") > > avoids allocating bootmem memory for non existent nodes. > > But when DEBUG_PER_CPU_MAPS=y is enabled, my powerNV system failed to boot > because in sched_init_numa(), cpumask_or() operation was done on > unallocated nodes. > > Fix that by making cpumask_or() operation only on existing nodes. > > [ Tested with and w/o DEBUG_PER_CPU_MAPS=y on x86 and PowerPC. ] > > Reported-by: Jan Stancek > Tested-by: Jan Stancek > Signed-off-by: Raghavendra K T > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Cc: > Link: http://lkml.kernel.org/r/1452884483-11676-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com > Signed-off-by: Ingo Molnar > --- > kernel/sched/core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 44253ad..474658b 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -6840,7 +6840,7 @@ static void sched_init_numa(void) > > sched_domains_numa_masks[i][j] = mask; > > - for (k = 0; k < nr_node_ids; k++) { > + for_each_node(k) { > if (node_distance(j, k) > sched_domains_numa_distance[i]) > continue; > > > > Hello Greg, Above commit fixes the debug kernel crash in 4.4 kernel [ when DEBUG_PER_CPU_MAPS=y to be precise]. This is a regression in 4.4 from 4.3 and should be ideally present in 4.4-stable. Could you please pull in this change.? -- 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