Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760025Ab2HXSyP (ORCPT ); Fri, 24 Aug 2012 14:54:15 -0400 Received: from co1ehsobe005.messaging.microsoft.com ([216.32.180.188]:56673 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760008Ab2HXSyI (ORCPT ); Fri, 24 Aug 2012 14:54:08 -0400 X-Forefront-Antispam-Report: CIP:163.181.249.109;KIP:(null);UIP:(null);IPV:NLI;H:ausb3twp02.amd.com;RD:none;EFVD:NLI X-SpamScore: 0 X-BigFish: VPS0(zzzz1202hzz8275bh8275dhz2dh668h839hd24he5bhf0ah11b5h1155h) X-WSS-ID: 0M99WI2-02-15E-02 X-M-MSG: From: Robert Richter To: Ingo Molnar CC: LKML , oprofile-list , Robert Richter , Andi Kleen Subject: [PATCH 2/2] oprofile: Remove 'WQ on CPUx, prefer CPUy' warning Date: Fri, 24 Aug 2012 20:53:31 +0200 Message-ID: <1345834411-24940-3-git-send-email-robert.richter@amd.com> X-Mailer: git-send-email 1.7.8.6 In-Reply-To: <1345834411-24940-1-git-send-email-robert.richter@amd.com> References: <1345834411-24940-1-git-send-email-robert.richter@amd.com> MIME-Version: 1.0 Content-Type: text/plain X-OriginatorOrg: amd.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1749 Lines: 53 Under certain workloads we see the following warnings: WQ on CPU0, prefer CPU1 WQ on CPU0, prefer CPU2 WQ on CPU0, prefer CPU3 It warns the user that the wq to access a per-cpu buffers runs not on the same cpu. This happens if the wq is rescheduled on a different cpu than where the buffer is located. This was probably implemented to detect performance issues. Not sure if there actually is one as the buffers are copied to a single buffer anyway which should be the actual bottleneck. We wont change WQ implementation. Since a user can do nothing the warning is pointless. Removing it. Cc: Andi Kleen Signed-off-by: Robert Richter --- drivers/oprofile/cpu_buffer.c | 11 +++-------- 1 files changed, 3 insertions(+), 8 deletions(-) diff --git a/drivers/oprofile/cpu_buffer.c b/drivers/oprofile/cpu_buffer.c index b8ef8dd..8aa73fa 100644 --- a/drivers/oprofile/cpu_buffer.c +++ b/drivers/oprofile/cpu_buffer.c @@ -451,14 +451,9 @@ static void wq_sync_buffer(struct work_struct *work) { struct oprofile_cpu_buffer *b = container_of(work, struct oprofile_cpu_buffer, work.work); - if (b->cpu != smp_processor_id()) { - printk(KERN_DEBUG "WQ on CPU%d, prefer CPU%d\n", - smp_processor_id(), b->cpu); - - if (!cpu_online(b->cpu)) { - cancel_delayed_work(&b->work); - return; - } + if (b->cpu != smp_processor_id() && !cpu_online(b->cpu)) { + cancel_delayed_work(&b->work); + return; } sync_buffer(b->cpu); -- 1.7.8.6 -- 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/