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 BE506C4332F for ; Mon, 6 Nov 2023 16:30:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232032AbjKFQaA (ORCPT ); Mon, 6 Nov 2023 11:30:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229642AbjKFQ37 (ORCPT ); Mon, 6 Nov 2023 11:29:59 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB51FF4 for ; Mon, 6 Nov 2023 08:29:56 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EC74C433C8; Mon, 6 Nov 2023 16:29:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1699288194; bh=Am+PVPrUwLAGoDv2qBi3sFoGiy6NZ955i06iPxaiaOA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=L23jUDrB8Mav93Fm9EA4+JtO5wcbJ4uxFiPh2YwS2mRBqkkznISmXw/rqePNCoF9I 3UWlvS8ikp0reHVCrqmGrrQ39dFkELOsKR+C0yeRxxu9dwOd2XC662t96khucUvodM d8rSu1n4/ivCudpCvPinFeRFSA+YNk8KWRfytf13OcSkgtMmDSvsj1wnjLlGzJYnTz p12tR1H5IlSl6Mw/XiMTEdVO/emvzt2odOgzCzkLqHqa0VG393eXQIL+wu0HmdntQZ /ChfYzeQSH7JUJx/jQ+9742S/KMM/agIfmfYbhd9Ec6fdr76YHrpH6BZFgDxFPoozp JTyljuCuS08TA== Message-ID: <9a7222ed-88f8-4a3f-9d83-09b7fb977c27@kernel.org> Date: Mon, 6 Nov 2023 17:29:49 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 7/7] sched/fair: Fair server interface Content-Language: en-US, pt-BR, it-IT To: Peter Zijlstra Cc: Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org, Luca Abeni , Tommaso Cucinotta , Thomas Gleixner , Joel Fernandes , Vineeth Pillai , Shuah Khan , Phil Auld References: <26adad2378c8b15533e4f6216c2863341e587f57.1699095159.git.bristot@kernel.org> <20231106154042.GH3818@noisy.programming.kicks-ass.net> From: Daniel Bristot de Oliveira In-Reply-To: <20231106154042.GH3818@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/6/23 16:40, Peter Zijlstra wrote: > On Sat, Nov 04, 2023 at 11:59:24AM +0100, Daniel Bristot de Oliveira wrote: >> Add an interface for fair server setup on debugfs. >> >> Each rq have three files under /sys/kernel/debug/sched/rq/CPU{ID}: >> >> - fair_server_runtime: set runtime in ns >> - fair_server_period: set period in ns >> - fair_server_defer: on/off for the defer mechanism >> > > This then leaves /proc/sys/kernel/sched_rt_{period,runtime}_us to be the > total available bandwidth control, right? right, but thinking aloud... given that the per-cpu files are already allocating the bandwidth on the dl_rq, the spare time for fair scheduler is granted. Still, we can have them there as a safeguard to not overloading the deadline scheduler... (thinking aloud 2) as long as global is a thing... as we get away from it, that global limitation will make less sense - still better to have a form of limitation so people are aware of bandwidth until there. > But then shouldn've we also rip out the throttle thingy right quick? > I was thinking about moving the entire throttling machinery inside CONFIG_RT_GROUP_SCHED for now, because GROUP_SCHED depends on it, no? With the next step on moving the dl server as the base for the hierarchical scheduling... That will rip out the CONFIG_RT_GROUP_SCHED... with a thing with a per-cpu interface. Does it make sense?