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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 2C9ADC432C0 for ; Sun, 17 Nov 2019 10:20:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 026CD206D6 for ; Sun, 17 Nov 2019 10:20:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726097AbfKQKUC (ORCPT ); Sun, 17 Nov 2019 05:20:02 -0500 Received: from foss.arm.com ([217.140.110.172]:50278 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726067AbfKQKUC (ORCPT ); Sun, 17 Nov 2019 05:20:02 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2E465328; Sun, 17 Nov 2019 02:20:01 -0800 (PST) Received: from [10.0.2.15] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3100E3F6C4; Sun, 17 Nov 2019 02:20:00 -0800 (PST) Subject: Re: [GIT PULL] scheduler fixes To: Ingo Molnar Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Andrew Morton References: <20191116213742.GA7450@gmail.com> <20191117094549.GB126325@gmail.com> From: Valentin Schneider Message-ID: <4e4b0828-abba-e27d-53f6-135df06eba1a@arm.com> Date: Sun, 17 Nov 2019 10:19:48 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191117094549.GB126325@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 17/11/2019 09:45, Ingo Molnar wrote: > I've picked v2 up instead. I suspect it's not really consequential as > enums don't really get truncated by compilers, right? Is there any other > negative runtime side effect possible from the imprecise enum/uint > typing? > AFAIUI the requirement for the enum type is that it has to be an int type that covers all its values, so I could see some funky optimization (e.g. check the returned value is < 512 but it's assumed the type for the enum is 8 bits so this becomes always true). Then again we don't have any explicit check on those returned values, plus they fit in 11 bits, so as you say it's mostly likely inconsequential (and I didn't see any compile diff). My "worry" wasn't really about this patch, it was more about the following one - it didn't like the idea of merging an unneeded patch (with a Fixes: tag on top of it). >>> sched/topology, cpuset: Account for housekeeping CPUs to avoid empty cpumasks >> >> And this one is no longer needed, as Michal & I understood (IOW the fix in >> rc6 is sufficient), see: >> >> c425c5cb-ba8a-e5f6-d91c-5479779cfb7a@arm.com > > Ok. > > I'm inclined to just reduce sched/urgent back to these three fixes: > > 6e1ff0773f49: sched/uclamp: Fix incorrect condition > b90f7c9d2198: sched/pelt: Fix update of blocked PELT ordering > ff51ff84d82a: sched/core: Avoid spurious lock dependencies > > and apply v2 of the uclamp_id type fix to sched/core. This would reduce > the risks of a Sunday pull request ... > This sounds good to me. Sorry for the hassle. > Thanks, > > Ingo >