Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752843Ab3FASZy (ORCPT ); Sat, 1 Jun 2013 14:25:54 -0400 Received: from mx1.redhat.com ([209.132.183.28]:28084 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753727Ab3FASZh (ORCPT ); Sat, 1 Jun 2013 14:25:37 -0400 Date: Sat, 1 Jun 2013 20:21:39 +0200 From: Oleg Nesterov To: Vince Weaver Cc: linux-kernel@vger.kernel.org, Peter Zijlstra , Paul Mackerras , Ingo Molnar , Arnaldo Carvalho de Melo , trinity@vger.kernel.org, Jiri Olsa Subject: [PATCH 2/2] hw_breakpoint: Use cpu_possible_mask in {reserve,release}_bp_slot() Message-ID: <20130601182139.GC4861@redhat.com> References: <20130601182057.GA4861@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130601182057.GA4861@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1641 Lines: 52 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(). Signed-off-by: Oleg Nesterov Cc: --- kernel/events/hw_breakpoint.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 29d3abe..4407e43 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -149,7 +149,7 @@ 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); @@ -235,7 +235,7 @@ 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); } -- 1.5.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/