From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 70A36C4CECE for ; Sun, 13 Oct 2019 17:44:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4875921848 for ; Sun, 13 Oct 2019 17:44:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728839AbfJMRoj (ORCPT ); Sun, 13 Oct 2019 13:44:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:36850 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728679AbfJMRoU (ORCPT ); Sun, 13 Oct 2019 13:44:20 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7E6A820882; Sun, 13 Oct 2019 17:44:20 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.92.2) (envelope-from ) id 1iJhul-000248-LW; Sun, 13 Oct 2019 13:44:19 -0400 Message-Id: <20191013174419.549609687@goodmis.org> User-Agent: quilt/0.65 Date: Sun, 13 Oct 2019 13:43:51 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , stable@vger.kernel.org, "Srivatsa S. Bhat (VMware)" Subject: [for-linus][PATCH 09/11] tracing/hwlat: Report total time spent in all NMIs during the sample References: <20191013174342.381019558@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: "Srivatsa S. Bhat (VMware)" nmi_total_ts is supposed to record the total time spent in *all* NMIs that occur on the given CPU during the (active portion of the) sampling window. However, the code seems to be overwriting this variable for each NMI, thereby only recording the time spent in the most recent NMI. Fix it by accumulating the duration instead. Link: http://lkml.kernel.org/r/157073343544.17189.13911783866738671133.stgit@srivatsa-ubuntu Fixes: 7b2c86250122 ("tracing: Add NMI tracing in hwlat detector") Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat (VMware) Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_hwlat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/trace_hwlat.c b/kernel/trace/trace_hwlat.c index fa95139445b2..a0251a78807d 100644 --- a/kernel/trace/trace_hwlat.c +++ b/kernel/trace/trace_hwlat.c @@ -150,7 +150,7 @@ void trace_hwlat_callback(bool enter) if (enter) nmi_ts_start = time_get(); else - nmi_total_ts = time_get() - nmi_ts_start; + nmi_total_ts += time_get() - nmi_ts_start; } if (enter) -- 2.23.0