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 C6ECBC46CA0 for ; Thu, 7 Dec 2023 21:47:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231928AbjLGVqy (ORCPT ); Thu, 7 Dec 2023 16:46:54 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58680 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235274AbjLGVqw (ORCPT ); Thu, 7 Dec 2023 16:46:52 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E1581171C for ; Thu, 7 Dec 2023 13:46:49 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 72207C433C8; Thu, 7 Dec 2023 21:46:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1701985609; bh=cb6OkXmUGJDQwqEXYwG+06ZB77FI6/Yop3Wrvy+jN+8=; h=Date:To:From:Subject:From; b=yrOetT9txH4devf7K1HIALj4H+ObeKXvoJNQ7sWEdxQC47NaELEQCCfISvpPsLT49 oOuKra7O2JGgnO58kQYGfkgH+bmi9rPEdDB651AzlZQpoRabcBBi6uorZDapMhhmU0 0xMUxv5pWq4RECJgIbsipKVOUN7/Ra22P0nQxD4o= Date: Thu, 07 Dec 2023 13:46:47 -0800 To: mm-commits@vger.kernel.org, tglx@linutronix.de, ming.lei@redhat.com, linux@rasmusvillemoes.dk, andriy.shevchenko@linux.intel.com, yury.norov@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: + lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch added to mm-nonmm-unstable branch Message-Id: <20231207214649.72207C433C8@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The patch titled Subject: lib/group_cpus.c: drop unneeded cpumask_empty() call in __group_cpus_evenly() has been added to the -mm mm-nonmm-unstable branch. Its filename is lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Yury Norov Subject: lib/group_cpus.c: drop unneeded cpumask_empty() call in __group_cpus_evenly() Date: Thu, 7 Dec 2023 12:39:00 -0800 The function is called twice. First time it's called with cpumask_present as a parameter, which can't be empty. Second time it's called with a mask created with cpumask_andnot(), which returns false if the result is an empty mask. We can safely drop redundant cpumask_empty() call from the __group_cpus_evenly() and save few cycles. Link: https://lkml.kernel.org/r/20231207203900.859776-7-yury.norov@gmail.com Signed-off-by: Yury Norov Cc: Andy Shevchenko Cc: Ming Lei Cc: Rasmus Villemoes Cc: Thomas Gleixner Signed-off-by: Andrew Morton --- lib/group_cpus.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) --- a/lib/group_cpus.c~lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly +++ a/lib/group_cpus.c @@ -252,9 +252,6 @@ static int __group_cpus_evenly(unsigned nodemask_t nodemsk = NODE_MASK_NONE; struct node_groups *node_groups; - if (cpumask_empty(cpu_mask)) - return 0; - nodes = get_nodes_in_cpumask(node_to_cpumask, cpu_mask, &nodemsk); /* @@ -394,9 +391,14 @@ struct cpumask *group_cpus_evenly(unsign curgrp = 0; else curgrp = nr_present; - cpumask_andnot(npresmsk, cpu_possible_mask, npresmsk); - ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask, - npresmsk, nmsk, masks); + + if (cpumask_andnot(npresmsk, cpu_possible_mask, npresmsk)) + /* If npresmsk is not empty */ + ret = __group_cpus_evenly(curgrp, numgrps, node_to_cpumask, + npresmsk, nmsk, masks); + else + ret = 0; + if (ret >= 0) nr_others = ret; _ Patches currently in -mm which might be from yury.norov@gmail.com are cpumask-introduce-for_each_cpu_and_from.patch lib-group_cpus-relax-atomicity-requirement-in-grp_spread_init_one.patch lib-group_cpus-optimize-inner-loop-in-grp_spread_init_one.patch lib-group_cpus-optimize-outer-loop-in-grp_spread_init_one.patch lib-cgroup_cpusc-dont-zero-cpumasks-in-group_cpus_evenly-on-allocation.patch lib-group_cpusc-drop-unneeded-cpumask_empty-call-in-__group_cpus_evenly.patch