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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 C33E0C433ED for ; Wed, 14 Apr 2021 02:22:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8501C6100B for ; Wed, 14 Apr 2021 02:22:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241565AbhDNCXQ (ORCPT ); Tue, 13 Apr 2021 22:23:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44612 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231475AbhDNCXO (ORCPT ); Tue, 13 Apr 2021 22:23:14 -0400 Received: from mail-oi1-x235.google.com (mail-oi1-x235.google.com [IPv6:2607:f8b0:4864:20::235]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26FEFC061574 for ; Tue, 13 Apr 2021 19:22:54 -0700 (PDT) Received: by mail-oi1-x235.google.com with SMTP id l131so14035632oih.0 for ; Tue, 13 Apr 2021 19:22:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0bUWQOMJ96PoYWOLH0fkfiPVKgABX0K+anxlEDeI/Qg=; b=fALajJhCjE651tZQn4n8kZ0nCYCn7m9uuoIUFn2aRTN8ihjoiH+sUfnWPgDPEaCzec sdI5Gxt8sIQwVH6CHxDhimR0Wgujf/INZA4TNZ5ZqwmThe3yATwb0DyGj6Ec9VELK16Z JML8l0h1gt36tV4dna877lE4WvUnbqzORoQgEwtjq2J2waZjfuhBCJcyccPJJYLLHNTp 4I6kBVd2yeJEEJBsH6P6U8QUebkFiPr3/nyk0saa6pOy+JXrlpeoCYFLL1I+2U/Umwnv A3N0sc97howmVDQ2cXjf6m4uCIOy7mE0XDxEBw3PI1d2ana6QtrLuuBjhfI7VKFczX2W QojA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=0bUWQOMJ96PoYWOLH0fkfiPVKgABX0K+anxlEDeI/Qg=; b=QW8ZPFJwbHQutex53cgIVceC6RcgnRNehfAS3cI38SfEqP+HJp4qGEfe0GYtSQ8JG2 wwIYqg3TyZPjbYntYrBxiWR3RM/vBQkoR4WeHFj/gJFurm5lZfCGoj3SSrcRn0jwlwR3 3/9ygSHQUpc7n4vFvttIRwdsuL9x1wECfC8nnbq9Ha655YIw2lXEg5oRc9hBONr7AF/y RFJkayLEMbWFhZHVDrZ558sAhsfuC+juXB35lmWJoWZC13UpynMF42OV/hrJYK5IgeuQ O61abbUXg5JYz6ZEMjyemXaIae8vswYwxGKOA3VIfLet/S5Jo9xGp+eaQ7HuVmTDKNZ7 bbhg== X-Gm-Message-State: AOAM531c0T6J8rrsJKrbJ1+1fwxM3rBeIy9mAS1hZsUiB7AXkppIGvgk lGMsVwJcHO7AoSQPSf32d3ClAnaXldgbRf0n X-Google-Smtp-Source: ABdhPJzCOho9gR1xs9yKINv72Nw0HQmbucdL2Qk3sdFZ54orn4/Z3RP6rE9UmM3b/G8IACw1MkmjBQ== X-Received: by 2002:aca:b807:: with SMTP id i7mr642266oif.98.1618366973543; Tue, 13 Apr 2021 19:22:53 -0700 (PDT) Received: from localhost.localdomain ([50.236.19.102]) by smtp.gmail.com with ESMTPSA id j20sm3196627ooc.29.2021.04.13.19.22.47 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 13 Apr 2021 19:22:53 -0700 (PDT) From: qianjun.kernel@gmail.com To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com Cc: linux-kernel@vger.kernel.org, jun qian Subject: [PATCH V2 1/1] sched/fair:Reduce unnecessary check preempt in the sched tick Date: Wed, 14 Apr 2021 10:22:29 +0800 Message-Id: <20210414022229.5469-1-qianjun.kernel@gmail.com> X-Mailer: git-send-email 2.20.1 (Apple Git-117) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: jun qian As you are already set the TIF_NEED_RESCHED, there is no need to check resched again. Signed-off-by: jun qian --- kernel/sched/fair.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 794c2cb945f8..1a69b5fffe4a 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -4360,19 +4360,26 @@ check_preempt_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr) { unsigned long ideal_runtime, delta_exec; struct sched_entity *se; + struct rq *rq = rq_of(cfs_rq); s64 delta; ideal_runtime = sched_slice(cfs_rq, curr); delta_exec = curr->sum_exec_runtime - curr->prev_sum_exec_runtime; if (delta_exec > ideal_runtime) { - resched_curr(rq_of(cfs_rq)); + if (!test_tsk_need_resched(rq->curr)) + resched_curr(rq_of(cfs_rq)); /* * The current task ran long enough, ensure it doesn't get * re-elected due to buddy favours. */ clear_buddies(cfs_rq, curr); return; - } + /* + * If here with TIF_NEED_RESCHED already set from the early entity_tick, + * there is no need to check again. + */ + } else if (test_tsk_need_resched(rq->curr)) + return; /* * Ensure that a task that missed wakeup preemption by a -- 2.18.2