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 F149FC4167B for ; Mon, 12 Dec 2022 17:47:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232628AbiLLRrd (ORCPT ); Mon, 12 Dec 2022 12:47:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50294 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232671AbiLLRrZ (ORCPT ); Mon, 12 Dec 2022 12:47:25 -0500 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F311013F45; Mon, 12 Dec 2022 09:47:23 -0800 (PST) Received: by mail-pl1-x632.google.com with SMTP id 17so5391641pll.0; Mon, 12 Dec 2022 09:47:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=/KIRaN3WDqmUUaVTW9iHZr2+iJnqBAu9ZpvcFSzezwk=; b=Spn2yU4s03YU4KB7Cu6/Z7pSfm1ajmNiJQBOnZeeVN05NmjaByr8rJW/Jw6lq1qftL mNggN1kjtKStCP+SRLpx/fMTD5WuEMe3Vyen2kf4KAbNe330+TfLFjHH4jXXwCIHBzU4 m/iK3Yv8iRKoNq/zQ2H6zO4YH4Aksf0sKCITeOBaYl9E6JQ4MD363X3ik37owpNYmkuw +sjtCLo3V/X94d6XyZ3VXw6DpmsNM1i9beEh9X3+bXf4YkVVvyyRQK38M/jZpBByy3jb ULWbZ+Kbm/mZM3WCI9+2z08RZHwTtfrqj9N4r7ZsEnSiUYdWODN/f/iQfi4OgQP38tVJ 0aBA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=/KIRaN3WDqmUUaVTW9iHZr2+iJnqBAu9ZpvcFSzezwk=; b=IH1WqNlks4t6Z2P6GyhpNEXGEvXnTm8iUZp2DUHGaG3JxLMOFkmWWfk5sbeF/wvudp /7sGLvoqzux84AfULfJawQdCDcasP9iSjFFsO3Tc5MqhMlwPCSe46PIuahT41oUtkAQr 4AgFmzZQu4efEqN77nXetvjLd2yHnM82Ek60sPJeSDrMQ4iX4JtOV5hHVpIY3ebhRZtF BhIy17E1KooiyFIIIkwKlYV9voMcoIlGYg+p16nqvXg1MABjGbTYrTsGbzQql9nwTW58 G0hWjthn/dHEJiw6x2iXpWfZFHSTwZphmooaTyhWGOmqYXrlDDiMeYN56HmYUt9MNjxu gzUg== X-Gm-Message-State: ANoB5pmRFnBIRk9omZU5O0D6PVXumY359IXhoqzESgWoYNsS1BQSFXSc AbHpvS3hz5ECmiyG2z97Yko= X-Google-Smtp-Source: AA0mqf5xxuWgOaHIdN3scLmRqly7RT8hB0qT/H62AfRpB24zxpIZ8cryvYmGAcXp4nYVppd3kvejww== X-Received: by 2002:a17:902:dac3:b0:189:62f7:e5fc with SMTP id q3-20020a170902dac300b0018962f7e5fcmr22471235plx.14.1670867243287; Mon, 12 Dec 2022 09:47:23 -0800 (PST) Received: from localhost ([2620:10d:c090:400::5:9159]) by smtp.gmail.com with ESMTPSA id jf15-20020a170903268f00b00189f69c1aa0sm6650577plb.270.2022.12.12.09.47.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 12 Dec 2022 09:47:22 -0800 (PST) Sender: Tejun Heo Date: Mon, 12 Dec 2022 07:47:21 -1000 From: Tejun Heo To: Peter Zijlstra Cc: torvalds@linux-foundation.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, joshdon@google.com, brho@google.com, pjt@google.com, derkling@google.com, haoluo@google.com, dvernet@meta.com, dschatzberg@meta.com, dskarlat@cs.cmu.edu, riel@surriel.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH 08/31] sched: Expose css_tg() and __setscheduler_prio() in kernel/sched/sched.h Message-ID: References: <20221130082313.3241517-1-tj@kernel.org> <20221130082313.3241517-9-tj@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 12, 2022 at 12:49:59PM +0100, Peter Zijlstra wrote: > On Tue, Nov 29, 2022 at 10:22:50PM -1000, Tejun Heo wrote: > > These will be used by a new sched_class. > > Uhhh.. wtf does a policy need __setscheduler_prio() for? Whether a task is on sched_ext or not is determined by a few factors - the chosen sched class of the task, whether the BPF scheduler is loaded and whether it's using scx_bpf_switch_all(). That selection logic is implemented in __setscheduler_prio(). When the BPF scheduler gets initialized and exited, the selection changes and sched_ext needs to walk the tasks reapplying the selection logic, so the export. This ties together with the sched_enq_and_set_task() that you replied to in another thread. Imma continue there. -- tejun