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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 3A39AC34047 for ; Wed, 19 Feb 2020 13:55:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D1142176D for ; Wed, 19 Feb 2020 13:55:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727864AbgBSNzR (ORCPT ); Wed, 19 Feb 2020 08:55:17 -0500 Received: from outbound-smtp50.blacknight.com ([46.22.136.234]:54095 "EHLO outbound-smtp50.blacknight.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726786AbgBSNzQ (ORCPT ); Wed, 19 Feb 2020 08:55:16 -0500 Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp50.blacknight.com (Postfix) with ESMTPS id E6140FB1DC for ; Wed, 19 Feb 2020 13:55:14 +0000 (GMT) Received: (qmail 8740 invoked from network); 19 Feb 2020 13:55:14 -0000 Received: from unknown (HELO stampy.112glenside.lan) (mgorman@techsingularity.net@[84.203.18.57]) by 81.17.254.9 with ESMTPA; 19 Feb 2020 13:55:14 -0000 From: Mel Gorman To: Peter Zijlstra Cc: Ingo Molnar , Vincent Guittot , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Valentin Schneider , Phil Auld , Hillf Danton , LKML , Mel Gorman Subject: [PATCH 02/13] sched/numa: Trace when no candidate CPU was found on the preferred node Date: Wed, 19 Feb 2020 13:54:31 +0000 Message-Id: <20200219135442.18107-3-mgorman@techsingularity.net> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200219135442.18107-1-mgorman@techsingularity.net> References: <20200219135442.18107-1-mgorman@techsingularity.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org sched:sched_stick_numa is meant to fire when a task is unable to migrate to the preferred node. The case where no candidate CPU could be found is not traced which is an important gap. The tracepoint is not fired when the task is not allowed to run on any CPU on the preferred node or the task is already running on the target CPU but neither are interesting corner cases. Signed-off-by: Mel Gorman --- kernel/sched/fair.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index ef3eb36ba5c4..d41a2b37694f 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -1848,8 +1848,10 @@ static int task_numa_migrate(struct task_struct *p) } /* No better CPU than the current one was found. */ - if (env.best_cpu == -1) + if (env.best_cpu == -1) { + trace_sched_stick_numa(p, env.src_cpu, -1); return -EAGAIN; + } best_rq = cpu_rq(env.best_cpu); if (env.best_task == NULL) { -- 2.16.4