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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A317C433EF for ; Wed, 26 Jan 2022 23:51:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232004AbiAZXvB (ORCPT ); Wed, 26 Jan 2022 18:51:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229812AbiAZXu7 (ORCPT ); Wed, 26 Jan 2022 18:50:59 -0500 Received: from mail-pl1-x630.google.com (mail-pl1-x630.google.com [IPv6:2607:f8b0:4864:20::630]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D6C1C06161C for ; Wed, 26 Jan 2022 15:50:59 -0800 (PST) Received: by mail-pl1-x630.google.com with SMTP id c3so1007694pls.5 for ; Wed, 26 Jan 2022 15:50:59 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=message-id:date:mime-version:user-agent:content-language:to:cc :references:from:subject:in-reply-to:content-transfer-encoding; bh=cBxJNeicoRzjXh+eEmDsU4Z8ycQDuwzwWKSyLyKYjXU=; b=WDTTt0fddCEhZQRAz+lyxdMB8Et0DAN1Bv3xBNQXrslbekeFaKcxFedz7j7v9I5ObM VgdLgPgxv5ZWO48+/hYqObsjQwiomzjtOveQ5BcOli0h0QH9he40zBt765mxWC0Czy3W g86g/debboCyRaCX18VAlylAtTIs9gKZarTr12u3LjIr/cqAHsF3V6WVBwMg1a92O9hr 0BEME9fAn9moT4q7Bg4V0+lFIJExTI8c21dH66vjwtOml+7uRRs8rIsRXQJC2hS3BYhJ CejyYws0tGz/b6cFq6pPPYeKR7gNGzH2wTbbAVDbtJNjOVkHYd8dpPcAwaOXkORXMTRN 0AfQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent :content-language:to:cc:references:from:subject:in-reply-to :content-transfer-encoding; bh=cBxJNeicoRzjXh+eEmDsU4Z8ycQDuwzwWKSyLyKYjXU=; b=xonMaCkjRT5fyNsFZavL+t3mzohSbnmA2eKGI0bTqOTv3+uwguvbtIi9/O0E+3jJwb 9KHBrvjpYtEKg914Uw5I9g6brkF6ShFtBS23n8mGLdtzZNPCe92Xmx4K4pNbIpThtQBt OHop4qX2J9BWQ6X0al1i3VXqDBVsKHZl9feOBxcgC5uffuaJ3R3PWtztwk73xjUsXfy0 3chrkwzvb5/DUdcogL14Ihit7UGvRhekHndDQWqIkj+vgTjlDPesqBYYmNujQSyirnng aNLkNNhLain1m9hUNv8v6o8cZz3UuzHgsKq9vcXtbXYG5NevQPO8Xn3YH7FVifaFzgML XHlA== X-Gm-Message-State: AOAM532U/zqCZnLljthXjZPTxFFjUTGZyD2ADscs8W7Yn7heMEAOEn9F lZL1K4yLi5/ElLZO8nXViWwk3Q== X-Google-Smtp-Source: ABdhPJykrJ2uOm8OEbe0IzU4Bthtxc99KDRuTVbvLsgTgp6ISyZ9HrqIrN5a+OcWk6ZkhecwMja/zA== X-Received: by 2002:a17:902:ea0b:: with SMTP id s11mr1274542plg.133.1643241058942; Wed, 26 Jan 2022 15:50:58 -0800 (PST) Received: from [192.168.254.17] ([50.39.160.154]) by smtp.gmail.com with ESMTPSA id s7sm3381389pfu.133.2022.01.26.15.50.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 26 Jan 2022 15:50:58 -0800 (PST) Message-ID: Date: Wed, 26 Jan 2022 15:50:57 -0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Content-Language: en-US To: Dietmar Eggemann , peterz@infradead.org Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Zhang Qiao , Daniel Jordan , stable@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+af7a719bc92395ee41b3@syzkaller.appspotmail.com References: <20220125193403.778497-1-tadeusz.struk@linaro.org> From: Tadeusz Struk Subject: Re: [PATCH v3] sched/fair: Fix fault in reweight_entity In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/26/22 05:53, Dietmar Eggemann wrote: > Can we then not get rid of `bool update_load` parameter of > set_load_weight() completely? > > @@ -1214,8 +1214,9 @@ int tg_nop(struct task_group *tg, void *data) > } > #endif > > -static void set_load_weight(struct task_struct *p, bool update_load) > +static void set_load_weight(struct task_struct *p) > { > + int task_new = READ_ONCE(p->__state) & TASK_NEW; > int prio = p->static_prio - MAX_RT_PRIO; > struct load_weight *load = &p->se.load; > > @@ -1232,7 +1233,7 @@ static void set_load_weight(struct task_struct *p, bool update_load) > * SCHED_OTHER tasks have to update their load when changing their > * weight > */ > - if (update_load && p->sched_class == &fair_sched_class) { > + if (!task_new && p->sched_class == &fair_sched_class) { > reweight_task(p, prio); > } else { > load->weight = scale_load(sched_prio_to_weight[prio]); That will also work. Let's agree on the best way to fix it. Peter, what's your preference? -- Thanks, Tadeusz