From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752374AbaCQVtc (ORCPT ); Mon, 17 Mar 2014 17:49:32 -0400 Received: from mx1.redhat.com ([209.132.183.28]:64112 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750706AbaCQVta (ORCPT ); Mon, 17 Mar 2014 17:49:30 -0400 From: Mark Salter To: Ingo Molnar , Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Mark Salter Subject: [PATCH] sched: use zalloc_cpumask_var for rootdomain cpumasks Date: Mon, 17 Mar 2014 17:48:35 -0400 Message-Id: <1395092915-26526-1-git-send-email-msalter@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In kernel/sched/core.c, there is: static int init_rootdomain(struct root_domain *rd) { memset(rd, 0, sizeof(*rd)); if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) goto out; if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) goto free_span; if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) goto free_online; if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) goto free_dlo_mask; In the CONFIG_CPUMASK_OFFSTACK=y case, there doesn't appear to be anything clearing the cpumasks. I think these should be zalloc_cpumask_var() calls. I noticed this while debugging a memory corruptor in unrelated code which cleared the span cpumask and triggered a BUG in the scheduler. I had turned on CONFIG_PAGE_POISONING and looking at the span cpumask at various points during early boot and saw that the mask was filled with POISON_FREE bytes before the secondary cores started coming up and setting their cpu bits in the mask. Signed-off-by: Mark Salter --- kernel/sched/core.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index f5c6635..9843755 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -5355,13 +5355,13 @@ static int init_rootdomain(struct root_domain *rd) { memset(rd, 0, sizeof(*rd)); - if (!alloc_cpumask_var(&rd->span, GFP_KERNEL)) + if (!zalloc_cpumask_var(&rd->span, GFP_KERNEL)) goto out; - if (!alloc_cpumask_var(&rd->online, GFP_KERNEL)) + if (!zalloc_cpumask_var(&rd->online, GFP_KERNEL)) goto free_span; - if (!alloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) + if (!zalloc_cpumask_var(&rd->dlo_mask, GFP_KERNEL)) goto free_online; - if (!alloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) + if (!zalloc_cpumask_var(&rd->rto_mask, GFP_KERNEL)) goto free_dlo_mask; init_dl_bw(&rd->dl_bw); -- 1.8.5.3