From nobody Sun Feb 8 20:35:49 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 B756CEB64D7 for ; Wed, 21 Jun 2023 07:16:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231239AbjFUHQs (ORCPT ); Wed, 21 Jun 2023 03:16:48 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53158 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229875AbjFUHQo (ORCPT ); Wed, 21 Jun 2023 03:16:44 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 249531703 for ; Wed, 21 Jun 2023 00:16:43 -0700 (PDT) Received: from canpemm500002.china.huawei.com (unknown [172.30.72.56]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4QmFDK6X21z1FDds; Wed, 21 Jun 2023 15:16:33 +0800 (CST) Received: from huawei.com (10.175.104.170) by canpemm500002.china.huawei.com (7.192.104.244) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.27; Wed, 21 Jun 2023 15:16:40 +0800 From: Miaohe Lin To: , , , CC: , , , , , , , Subject: [PATCH] sched/fair: fix returning possible non-optimal candidate Date: Wed, 21 Jun 2023 15:16:05 +0800 Message-ID: <20230621071605.3853119-1-linmiaohe@huawei.com> X-Mailer: git-send-email 2.23.0 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.175.104.170] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To canpemm500002.china.huawei.com (7.192.104.244) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" In best_fits < 0 case, best_thermal_cap > prev_thermal_cap is checked to determine whether best_energy_cpu should be returned. But prev_fits can be > 0 in this case and it should be preferred. Fixes: e5ed0550c04c ("sched/fair: unlink misfit task from cpu overutilized") Signed-off-by: Miaohe Lin --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 28ff831ee847..a4e300fc44be 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -7684,7 +7684,7 @@ static int find_energy_efficient_cpu(struct task_stru= ct *p, int prev_cpu) =20 if ((best_fits > prev_fits) || ((best_fits > 0) && (best_delta < prev_delta)) || - ((best_fits < 0) && (best_thermal_cap > prev_thermal_cap))) + ((best_fits < 0) && (prev_fits < 0) && (best_thermal_cap > prev_therm= al_cap))) target =3D best_energy_cpu; =20 return target; --=20 2.27.0