From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758663Ab3HMQEU (ORCPT ); Tue, 13 Aug 2013 12:04:20 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.122]:26202 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758692Ab3HMP6e (ORCPT ); Tue, 13 Aug 2013 11:58:34 -0400 X-Authority-Analysis: v=2.0 cv=e9yEuNV/ c=1 sm=0 a=Sro2XwOs0tJUSHxCKfOySw==:17 a=Drc5e87SC40A:10 a=Ciwy3NGCPMMA:10 a=S-olR7q8SFQA:10 a=5SG0PmZfjMsA:10 a=bbbx4UPp9XUA:10 a=meVymXHHAAAA:8 a=KGjhK52YXX0A:10 a=AVKxA0uPELEA:10 a=20KFwNOVAAAA:8 a=pGLkceISAAAA:8 a=VwQbUJbxAAAA:8 a=5cIBTxRJ4pZzZk2xk6UA:9 a=jEp0ucaQiEUA:10 a=MSl-tDqOz04A:10 a=LI9Vle30uBYA:10 a=jeBq3FmKZ4MA:10 a=Sro2XwOs0tJUSHxCKfOySw==:117 X-Cloudmark-Score: 0 X-Authenticated-User: X-Originating-IP: 67.255.60.225 Message-Id: <20130813155830.200189355@goodmis.org> User-Agent: quilt/0.60-1 Date: Tue, 13 Aug 2013 11:57:36 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Vince Weaver , Oleg Nesterov , Frederic Weisbecker , Ingo Molnar Subject: [42/88] hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot() References: <20130813155654.069291373@goodmis.org> Content-Disposition: inline; filename=0042-hw_breakpoint-Use-cpu_possible_mask-in-reserve-relea.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.6.11.7-rc1 stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov [ Upstream commit c790b0ad23f427c7522ffed264706238c57c007e ] fetch_bp_busy_slots() and toggle_bp_slot() use for_each_online_cpu(), this is obviously wrong wrt cpu_up() or cpu_down(), we can over/under account the per-cpu numbers. For example: # echo 0 >> /sys/devices/system/cpu/cpu1/online # perf record -e mem:0x10 -p 1 & # echo 1 >> /sys/devices/system/cpu/cpu1/online # perf record -e mem:0x10,mem:0x10,mem:0x10,mem:0x10 -C1 -a & # taskset -p 0x2 1 triggers the same WARN_ONCE("Can't find any breakpoint slot") in arch_install_hw_breakpoint(). Reported-by: Vince Weaver Signed-off-by: Oleg Nesterov Acked-by: Frederic Weisbecker Cc: Link: http://lkml.kernel.org/r/20130620155009.GA6327@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Steven Rostedt --- kernel/events/hw_breakpoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 9a7b487..4f06bf9 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -147,7 +147,7 @@ fetch_bp_busy_slots(struct bp_busy_slots *slots, struct perf_event *bp, return; } - for_each_online_cpu(cpu) { + for_each_possible_cpu(cpu) { unsigned int nr; nr = per_cpu(nr_cpu_bp_pinned[type], cpu); @@ -233,7 +233,7 @@ toggle_bp_slot(struct perf_event *bp, bool enable, enum bp_type_idx type, if (cpu >= 0) { toggle_bp_task_slot(bp, cpu, enable, type, weight); } else { - for_each_online_cpu(cpu) + for_each_possible_cpu(cpu) toggle_bp_task_slot(bp, cpu, enable, type, weight); } -- 1.7.10.4