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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 F2D3DC2BA19 for ; Tue, 14 Apr 2020 16:13:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE49D20656 for ; Tue, 14 Apr 2020 16:13:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mE40WOyH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389352AbgDNQNc (ORCPT ); Tue, 14 Apr 2020 12:13:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54774 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S2388615AbgDNQNZ (ORCPT ); Tue, 14 Apr 2020 12:13:25 -0400 Received: from mail-wr1-x449.google.com (mail-wr1-x449.google.com [IPv6:2a00:1450:4864:20::449]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0038AC061A0C for ; Tue, 14 Apr 2020 09:13:24 -0700 (PDT) Received: by mail-wr1-x449.google.com with SMTP id f15so9017656wrj.2 for ; Tue, 14 Apr 2020 09:13:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=32Nk4yPycqu5U0xNKJFgggSPEJ2kI45tjBMiQl+YlNA=; b=mE40WOyH75uFRgF6wVIgUBWep7Ri5Ntb76JlyOq46CyKv4H4x1tSiyQsiDVJYfEH0B PUU2apk7coMOeSEqrsIZICCfJ4J37ROVKUK7U94JmzNd0C7pkreMZTRQIuo6UXtGL/g3 YqU2bRic0wZVSeBaY+BJF+1+xwRll9gMxui/OnXIN6/TLAc4dqKPGVNlYouHRIbWY0W+ Tz6S6s2icon2Z1V+YB/agukYvetCsmEhhoSHR9GCRN/qZVnzoa+rKJwRQpeKlDH+ZNZV l1ZXyUlo6qifGBodsmsS2ENWoJaSekGQ+CZoQLmhnJ4XxVSxQTXRynejRHqHcQGKLgk6 IDZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=32Nk4yPycqu5U0xNKJFgggSPEJ2kI45tjBMiQl+YlNA=; b=KgpTg7zuNV+bC3VWstwKfUg10UvjzW/lsUJ2BLhTCUVbGhckd7AD0UqCi/v7tMk2S6 jG4sGcx1VfE9dQLfldILOPOTL8MOJtY5fFxd/O7XEnMt2uMlvQKDyhhC/niDyWXLC94S tyZ9kn2d7HYWPzOdPVSIG2cZymw1Ax+2eMqtbvegJFSvrmoyaTNOiJRQshEC8vQ5XsB6 Zrd9baGMITSz0H5sAZHNQn7rHAoumj47yUxnDA/dWGXTGXUtUzGuqJnvaW0WAOG11VRH 6iK4rucCeGSVoktC60BEe/gviluyYeUTtbiVrAIxzbQ7XtxDlaN/w0w499Ij4Z0rMhEn 5isg== X-Gm-Message-State: AGi0PuY0NDDHtXmd/HdTYRYqOGeXoD+8c0LOnNvDHWDiP4LOuWwqyPk1 3K7kXXtqdR46vbRxnTwKKmRR50ZNxr4g X-Google-Smtp-Source: APiQypKwAfnFzmYYa+L3bVNgwfMAQPIvFvcWx4Ta3qexNvUbtsUABlfhkQUSstih8SCkRqSQdtA7xqceZd13 X-Received: by 2002:adf:9321:: with SMTP id 30mr23209645wro.330.1586880802935; Tue, 14 Apr 2020 09:13:22 -0700 (PDT) Date: Tue, 14 Apr 2020 17:13:20 +0100 Message-Id: <20200414161320.251897-1-qperret@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.26.0.110.g2183baf09c-goog Subject: [PATCH] sched/core: Fix reset-on-fork from RT with uclamp From: Quentin Perret To: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org Cc: dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, ctheegal@codeaurora.org, dianders@chromium.org, patrick.bellasi@matbug.net, valentin.schneider@arm.com, qais.yousef@arm.com, linux-kernel@vger.kernel.org, qperret@google.com, kernel-team@android.com Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org uclamp_fork() resets the uclamp values to their default when the reset-on-fork flag is set. It also checks whether the task has a RT policy, and sets its uclamp.min to 1024 accordingly. However, during reset-on-fork, the task's policy is lowered to SCHED_NORMAL right after, hence leading to an erroneous uclamp.min setting for the new task if it was forked from RT. Fix this by removing the unnecessary check on rt_policy() in uclamp_fork() as this doesn't make sense if the reset-on-fork flag is set. Reported-by: Chitti Babu Theegala Signed-off-by: Quentin Perret --- kernel/sched/core.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 3a61a3b8eaa9..9ea3e484eea2 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -1234,10 +1234,6 @@ static void uclamp_fork(struct task_struct *p) for_each_clamp_id(clamp_id) { unsigned int clamp_value = uclamp_none(clamp_id); - /* By default, RT tasks always get 100% boost */ - if (unlikely(rt_task(p) && clamp_id == UCLAMP_MIN)) - clamp_value = uclamp_none(UCLAMP_MAX); - uclamp_se_set(&p->uclamp_req[clamp_id], clamp_value, false); } } -- 2.26.0.110.g2183baf09c-goog