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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 C3B4EC43460 for ; Thu, 22 Apr 2021 17:29:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C79561184 for ; Thu, 22 Apr 2021 17:29:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238683AbhDVRaT (ORCPT ); Thu, 22 Apr 2021 13:30:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48270 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238394AbhDVRaM (ORCPT ); Thu, 22 Apr 2021 13:30:12 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6985FC06174A for ; Thu, 22 Apr 2021 10:29:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=1DyE3USgzq4ZI15aHBo2m2fFbLZpZ606BX/3TbcfNRo=; b=Hki+pKGLtfeEUySz5nHMSq8B8A SAuU8Ck4wEsYQF5dnCBDHbA3S34qyPKgPq/uYE0NJqAbbZ0Dfltr2UMPJKa4K3LzKStw27kTQJYZH V6JMjrZtBLpP/9TLhUT52K4PnGWk1R7DuIOmr1TOxQbzpztqgIVWkpbQEfbnpgxXJa++1rXEHVpcr UhrW3qPY8RAvw1WjFIbsaRVHFr50ZRFxq87bS5ZbNtZ/i1Fj8kE51KHbD56yYRJaoUxbuQcifGNC1 fv4zVg1YVSIQC5ctQpUdiMb04rw9F7gx4SJlXs+g/3I6rM56xNGX7ZJY6shJBcL1WgI1JNHYQivBH YcALgr7A==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lZd8s-00HBLD-S6; Thu, 22 Apr 2021 17:29:31 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 4306A3001E2; Thu, 22 Apr 2021 19:29:29 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 312D42D04872B; Thu, 22 Apr 2021 19:29:29 +0200 (CEST) Date: Thu, 22 Apr 2021 19:29:29 +0200 From: Peter Zijlstra To: Don Hiatt Cc: Joel Fernandes , "Hyser,Chris" , Josh Don , mingo@kernel.org, vincent.guittot@linaro.org, valentin.schneider@arm.com, mgorman@suse.de, linux-kernel@vger.kernel.org, tglx@linutronix.de Subject: Re: [PATCH 00/19] sched: Core Scheduling Message-ID: References: <20210422120459.447350175@infradead.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 Thu, Apr 22, 2021 at 09:43:59AM -0700, Don Hiatt wrote: > On Thu, Apr 22, 2021 at 5:37 AM Peter Zijlstra wrote: > > > > Hai, > > > > This is an agressive fold of all the core-scheduling work so far. I've stripped > > a whole bunch of tags along the way (hopefully not too many, please yell if you > > feel I made a mistake), including tested-by. Please retest. > > > > Changes since the last partial post is dropping all the cgroup stuff and > > PR_SCHED_CORE_CLEAR as well as that exec() behaviour in order to later resolve > > the cgroup issue. > > > Hi Peter, > > Is there a reason that PR_SCHED_CORE_CLEAR got removed? It's handy to > be able to clear cookies. I agree, but if we're forced to do cgroup with cookie inherit, when CLEAR allows a trivial escape. Until that whole cgroup thing is sorted, it is easiest to not have CLEAR, lest we have to change/augment CLEAR semantics in unfortunate ways, which is always harder once an API is out there. Also, see the entire previous discussion here: https://lore.kernel.org/lkml/20210401131012.395311786@infradead.org/