From nobody Mon Apr 6 14:11:59 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA5C5C54EE9 for ; Wed, 7 Sep 2022 11:20:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229863AbiIGLUh (ORCPT ); Wed, 7 Sep 2022 07:20:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44100 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229811AbiIGLU1 (ORCPT ); Wed, 7 Sep 2022 07:20:27 -0400 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02A8F83BC0 for ; Wed, 7 Sep 2022 04:20:26 -0700 (PDT) Received: by mail-pl1-x636.google.com with SMTP id iw17so7543928plb.0 for ; Wed, 07 Sep 2022 04:20:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date; bh=75oh6xQWlTnSSymHGyItVY3zWSzkWl5meciwNnzeuy0=; b=PdxzqPPzNxrao+KcCVwt2ythahQZX8MMyQBWw2fuFSGEHMrh6N/zQO/9BwzPDL6cQ5 fcSu/krE12h5g7NkLUoQnzrIrPFOzyVjYTce5N4zhFJ7zUgcbd22dO/x0W69vsmb0yiq vN3kn6NjF5Qm460FtxPADuHzw5e7pnOBOlakfT+xXDR54tp59bcYDYLPa3S06q1XXoVi uZnnirxkh+tklpOVjtip5mu1eR92LpsXkF3IYzWfQJQVTJ1pnpPf7HJa1BMhnvRtJ5ni gw4oc1LzlPuS3NyO197z6LhaG5A7wE/rh19p2yUYsNdsuH8mmKa5wl/moNchiSwEnbiS kdLA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date; bh=75oh6xQWlTnSSymHGyItVY3zWSzkWl5meciwNnzeuy0=; b=RuVFr7inTJfYCbVIz9CZxd+yO5RMq4XNs+wxLCnDo2+2CWU046m1iHKSIKDZodJpT2 ttdRhZ2jIULv0muhErkEIfz+JNs0EislSylbXbUHO/xzGCKWiOQwEiQlwM1c9RdZdbG3 bVUotLDo+IzjAh7rAu2RfRAK/2t8IU9UkvxkpQ+WuEFN1r2QweN60Luze33poawQaeL5 +0beNABGYaTiR5aWZfegoqllFKmJEDk+u9KHaho6apVp6uKf+gQKLblV1temWwdyuBxd YA7L3iG69XgTyo54pKyjXMGVKZJerCHr1DhSb/A0/UQhyy+uCGxCOITOeyY/83scgbIU LeRA== X-Gm-Message-State: ACgBeo2o2YyATKv+ROPqWwfLFnHlK+cJqaQGyw5tVD2hkm4trIDqwmit TJ/e6lUyw230dWHWWgsL40f5VA== X-Google-Smtp-Source: AA6agR4GX94IaU6dQoeitqb7LX4chBXmrXy90EVoZ0eQdBctRNpyeB6hnT7s/7zVCpyVOHFUH6Xg8Q== X-Received: by 2002:a17:902:bc84:b0:174:505b:2d67 with SMTP id bb4-20020a170902bc8400b00174505b2d67mr3393134plb.33.1662549625548; Wed, 07 Sep 2022 04:20:25 -0700 (PDT) Received: from C02DV8HUMD6R.bytedance.net ([139.177.225.254]) by smtp.gmail.com with ESMTPSA id d12-20020a63f24c000000b0042ba0a822cbsm10334731pgk.8.2022.09.07.04.20.21 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Wed, 07 Sep 2022 04:20:25 -0700 (PDT) From: Abel Wu To: Peter Zijlstra , Mel Gorman , Vincent Guittot Cc: Josh Don , Chen Yu , Yicong Yang , linux-kernel@vger.kernel.org, Abel Wu , Mel Gorman Subject: [PATCH v4 2/5] sched/fair: Avoid double search on same cpu Date: Wed, 7 Sep 2022 19:19:57 +0800 Message-Id: <20220907112000.1854-3-wuyun.abel@bytedance.com> X-Mailer: git-send-email 2.37.3 In-Reply-To: <20220907112000.1854-1-wuyun.abel@bytedance.com> References: <20220907112000.1854-1-wuyun.abel@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The prev cpu is checked at the beginning of SIS, and it's unlikely to be idle before the second check in select_idle_smt(). So we'd better focus on its SMT siblings. Signed-off-by: Abel Wu Reviewed-by: Josh Don Acked-by: Mel Gorman --- kernel/sched/fair.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 9657c7de5f57..1ad79aaaaf93 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -6355,6 +6355,8 @@ static int select_idle_smt(struct task_struct *p, int= target) int cpu; =20 for_each_cpu_and(cpu, cpu_smt_mask(target), p->cpus_ptr) { + if (cpu =3D=3D target) + continue; if (available_idle_cpu(cpu) || sched_idle_cpu(cpu)) return cpu; } --=20 2.37.3