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 90E42C433FE for ; Wed, 16 Nov 2022 03:01:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231773AbiKPDBt (ORCPT ); Tue, 15 Nov 2022 22:01:49 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230424AbiKPDBr (ORCPT ); Tue, 15 Nov 2022 22:01:47 -0500 Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [IPv6:2a00:1450:4864:20::22b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58C0712A86 for ; Tue, 15 Nov 2022 19:01:45 -0800 (PST) Received: by mail-lj1-x22b.google.com with SMTP id s24so20110289ljs.11 for ; Tue, 15 Nov 2022 19:01:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:from:to:cc:subject:date :message-id:reply-to; bh=wbJwOo2aYI9tCPUydn6kWQ3LyG6BHpru5i6DVYdJudA=; b=R+on548QhW2DknFw9KvnXtq35R8t6uXck8lce5DV9K7xmUvTfHptoZB+Q9tZ/IBHn5 l77rODpnAH03N6Lu0ANaafhwSQKdqcPPNkyboOtGR6rLhsbI3rC5fzXRVEcH4TVxhlY8 O7ogXGOdlWNqmFnyBRQCdFUoe0qOgUAzaKfHKGZDN981WvQlL+aNjCw118DrYHPckOON OIDQC8oWT/i6Slty07ldKVyWcKuWE31SVgYtlyuCI375q0RYvwo98zMQpnPd9ZvYqW76 aWFylXZySDrpe+6v9w1Gel3/pYZYrh+48t7qEGOBzfJzg4gh4hcRPR5PDPYxfKhuBr9y b3eQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:cc:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=wbJwOo2aYI9tCPUydn6kWQ3LyG6BHpru5i6DVYdJudA=; b=L2OLQ0W5Id08L+CdJtDgX8Ngw7WhB4NZuC9t4wFQ2phBQFnFPmynIEWSmfkgBktjzD Z+qAL5nrBjSR7xZL1u0xoUW6t9fy0UOy+HL0+RSkNxtoRIitUJGRegClV0FvHls7r+To FeiV1aX12aqaN6y+AfHpQm0Fwadzne/NOhe/WfbKaflAhTQbBtAgrWBbSwvJ587LOiPu wmE5W2HWrfYqqJBBgD6EVcfFhUJ2pG00yoIdfEngDst700kfFFaQVKf4UIf58oJEEOgF jzJ1jV/fJS1LBL64AHz536UxRgb4iU7YolKz48xV9FSumvr5Wi0trSPuA9fs4ap9G0B4 iwSA== X-Gm-Message-State: ANoB5pkSznJeVPFRsRO0EWy890iay4Gi08Knlyux73hYOlV7xts+r9Df zkatx2/46x7quSBqRCOHHpB4QECpaz7xJbjeNJEhuQ== X-Google-Smtp-Source: AA0mqf5hKgOzFqoUlQJFzGijZWQaWdbLVsbwyZP+4R2PSwdHdX7xMpQrr/f1KlN3KMgmG2VUAO7apr6ry2vGrVuxYkM= X-Received: by 2002:a05:651c:12c5:b0:26e:33f:3c3c with SMTP id 5-20020a05651c12c500b0026e033f3c3cmr7207391lje.52.1668567703500; Tue, 15 Nov 2022 19:01:43 -0800 (PST) MIME-Version: 1.0 References: <20221026224449.214839-1-joshdon@google.com> <20221102165922.GA31833@blackbody.suse.cz> In-Reply-To: <20221102165922.GA31833@blackbody.suse.cz> From: Josh Don Date: Tue, 15 Nov 2022 19:01:31 -0800 Message-ID: Subject: Re: [PATCH v2] sched: async unthrottling for cfs bandwidth To: =?UTF-8?Q?Michal_Koutn=C3=BD?= Cc: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 2, 2022 at 9:59 AM Michal Koutn=C3=BD wrote: > > Also, can a particular cfs_rq be on both cfs_b->throttled_csd_list and > cfs_b->throttled_cfs_rq lists at any moment? > I wonder if having a single list_head node in cfs_rq would be feasible > (and hence enforcing this constraint in data). After more thought, I realized that we can't reuse the throttled_list list_head, since that would potentially break the lockless traversal of a concurrent list_for_each_entry_rcu() (ie. if we removed the element from the throttled list and then added it to the CSD list). - Josh