From patchwork Tue Jul 2 11:07:27 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Luis Henriques X-Patchwork-Id: 256378 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 537D92C013D for ; Tue, 2 Jul 2013 21:11:14 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UtyUD-00044a-H4; Tue, 02 Jul 2013 11:11:05 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UtyRn-0002lN-2M for kernel-team@lists.ubuntu.com; Tue, 02 Jul 2013 11:08:35 +0000 Received: from bl20-124-73.dsl.telepac.pt ([2.81.124.73] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UtyRm-0000kM-H5; Tue, 02 Jul 2013 11:08:34 +0000 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Subject: [PATCH 39/50] hw_breakpoint: Use cpu_possible_mask in {reserve, release}_bp_slot() Date: Tue, 2 Jul 2013 12:07:27 +0100 Message-Id: <1372763258-20664-40-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1372763258-20664-1-git-send-email-luis.henriques@canonical.com> References: <1372763258-20664-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.5 Cc: Oleg Nesterov , Ingo Molnar X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com 3.5.7.16 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov commit c790b0ad23f427c7522ffed264706238c57c007e upstream. 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 Link: http://lkml.kernel.org/r/20130620155009.GA6327@redhat.com Signed-off-by: Ingo Molnar Signed-off-by: Luis Henriques --- 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 bb38c4d..fc8bfcf 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); }