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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57C8AD3CC92 for ; Thu, 15 Jan 2026 00:53:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A539D6B0005; Wed, 14 Jan 2026 19:53:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 9D6816B0089; Wed, 14 Jan 2026 19:53:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8E2FB6B008A; Wed, 14 Jan 2026 19:53:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 7B9AF6B0005 for ; Wed, 14 Jan 2026 19:53:05 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay03.hostedemail.com (Postfix) with ESMTP id 19A1AB6514 for ; Thu, 15 Jan 2026 00:53:05 +0000 (UTC) X-FDA: 84332373930.14.9A2F2FD Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by imf14.hostedemail.com (Postfix) with ESMTP id 944F2100009 for ; Thu, 15 Jan 2026 00:52:59 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; spf=pass (imf14.hostedemail.com: domain of chenridong@huaweicloud.com designates 45.249.212.56 as permitted sender) smtp.mailfrom=chenridong@huaweicloud.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1768438383; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5Z9TTCdEGcAz3/MMv5gcSG5giGOZ78QNNfGsG4RLadc=; b=TAa1vhMynNRB10fc5UNgguKDVgpR01AmjrpJ1TVQe1H2ikxzKvXZkCaZ+Z9V+lZXnMamk6 EthEo2TBuK1ZpKMuWWirggEwZ5g6s/03RDa0Q8E71Dlw0DcSB1Z7UcKpjK0n0jRVZwaDvG cROxAQ/MU2hNYvqLco3e/LCaVjgXr/0= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=none; spf=pass (imf14.hostedemail.com: domain of chenridong@huaweicloud.com designates 45.249.212.56 as permitted sender) smtp.mailfrom=chenridong@huaweicloud.com; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1768438383; a=rsa-sha256; cv=none; b=TaGSF9a1QJqvsa1OLd3yZ0FlAUojSsZoalOx/Udg6RpAwjj24bAfSI94qx6DW8bdeb9xBP IdWepKTT83H1S9U+kAcvAkMvDhUDF9g1tk4zP5POkptTSxgbktW3+vt9FJeIAOmPDmWb54 9rxEvlT6Vg0FJ6D8+XSmUjtc/nxBh3w= Received: from mail.maildlp.com (unknown [172.19.163.170]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTPS id 4ds4FC6jxRzKHMdL for ; Thu, 15 Jan 2026 08:51:59 +0800 (CST) Received: from mail02.huawei.com (unknown [10.116.40.128]) by mail.maildlp.com (Postfix) with ESMTP id BCA634056E for ; Thu, 15 Jan 2026 08:52:52 +0800 (CST) Received: from [10.67.111.176] (unknown [10.67.111.176]) by APP4 (Coremail) with SMTP id gCh0CgBH9vZjOmhpd_JZDw--.10605S2; Thu, 15 Jan 2026 08:52:52 +0800 (CST) Message-ID: <2e8bf48a-b819-40b9-bb9b-f6ac6672059a@huaweicloud.com> Date: Thu, 15 Jan 2026 08:52:50 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 3/3] cgroup: use nodes_and() output where appropriate To: Waiman Long , Yury Norov , Andrew Morton , Alistair Popple , Byungchul Park , David Hildenbrand , Gregory Price , Johannes Weiner , Joshua Hahn , "Liam R. Howlett" , Lorenzo Stoakes , Matthew Brost , Michal Hocko , =?UTF-8?Q?Michal_Koutn=C3=BD?= , Mike Rapoport , Rakie Kim , Suren Baghdasaryan , Tejun Heo , Vlastimil Babka , Ying Huang , Zi Yan , cgroups@vger.kernel.org Cc: Yury Norov , Rasmus Villemoes , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20260114172217.861204-1-ynorov@nvidia.com> <20260114172217.861204-4-ynorov@nvidia.com> <51675d7c-5c9d-4596-8e5c-692c90b79e06@redhat.com> Content-Language: en-US From: Chen Ridong In-Reply-To: <51675d7c-5c9d-4596-8e5c-692c90b79e06@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CM-TRANSID:gCh0CgBH9vZjOmhpd_JZDw--.10605S2 X-Coremail-Antispam: 1UD129KBjvJXoW7ZF45KFyxArWkKFykGw4xCrg_yoW8tFy8pF 1kCry7Gay5AF1xGrWxXFyDW3s5Ja18Ja1UJr1UAF93JFnrJr10vF1UX34YgrWDCrW8Gr15 Jrn0vw1IvFy3Jr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUv0b4IE77IF4wAFF20E14v26ryj6rWUM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28lY4IEw2IIxxk0rwA2F7IY1VAKz4 vEj48ve4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_tr0E3s1l84ACjcxK6xIIjxv20xvEc7Cj xVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIE14v26rxl6s0DM28EF7xvwVC2z280aVCY1x 0267AKxVW0oVCq3wAS0I0E0xvYzxvE52x082IY62kv0487Mc02F40EFcxC0VAKzVAqx4xG 6I80ewAv7VC0I7IYx2IY67AKxVWUJVWUGwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFV Cjc4AY6r1j6r4UM4x0Y48IcVAKI48JM4IIrI8v6xkF7I0E8cxan2IY04v7MxkF7I0En4kS 14v26r4a6rW5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r4UMI8I3I0E5I 8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVW8ZVWr XwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2Ix0cI8IcVCY1x 0267AKxVW8JVWxJwCI42IY6xAIw20EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_ Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU0 s2-5UUUUU== X-CM-SenderInfo: hfkh02xlgr0w46kxt4xhlfz01xgou0bp/ X-Rspamd-Queue-Id: 944F2100009 X-Stat-Signature: ir8p6kb5udiywnhnhxj9oh7m8psk87uz X-Rspam-User: X-Rspamd-Server: rspam05 X-HE-Tag: 1768438379-368820 X-HE-Meta: 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 2026/1/15 6:33, Waiman Long wrote: > On 1/14/26 12:22 PM, Yury Norov wrote: >> Now that nodes_and() returns true if the result nodemask is not empty, >> drop useless nodes_intersects() in guarantee_online_mems() and >> nodes_empty() in update_nodemasks_hier(), which both are O(N). >> >> Signed-off-by: Yury Norov >> --- >>   kernel/cgroup/cpuset.c | 7 +++---- >>   1 file changed, 3 insertions(+), 4 deletions(-) >> >> diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c >> index 3e8cc34d8d50..e962efbb300d 100644 >> --- a/kernel/cgroup/cpuset.c >> +++ b/kernel/cgroup/cpuset.c >> @@ -456,9 +456,8 @@ static void guarantee_active_cpus(struct task_struct *tsk, >>    */ >>   static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask) >>   { >> -    while (!nodes_intersects(cs->effective_mems, node_states[N_MEMORY])) >> +    while (!nodes_and(*pmask, cs->effective_mems, node_states[N_MEMORY])) >>           cs = parent_cs(cs); >> -    nodes_and(*pmask, cs->effective_mems, node_states[N_MEMORY]); >>   } >>     /** >> @@ -2862,13 +2861,13 @@ static void update_nodemasks_hier(struct cpuset *cs, nodemask_t *new_mems) >>       cpuset_for_each_descendant_pre(cp, pos_css, cs) { >>           struct cpuset *parent = parent_cs(cp); >>   -        nodes_and(*new_mems, cp->mems_allowed, parent->effective_mems); >> +        bool has_mems = nodes_and(*new_mems, cp->mems_allowed, parent->effective_mems); >>             /* >>            * If it becomes empty, inherit the effective mask of the >>            * parent, which is guaranteed to have some MEMs. >>            */ >> -        if (is_in_v2_mode() && nodes_empty(*new_mems)) >> +        if (is_in_v2_mode() && !has_mems) >>               *new_mems = parent->effective_mems; >>             /* Skip the whole subtree if the nodemask remains the same. */ > Reviewed-by: Waiman Long > Reviewed-by: Chen Ridong -- Best regards, Ridong