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=-15.9 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=unavailable 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 D6EDFC35246 for ; Sun, 26 Jan 2020 22:44:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9AA1E2070A for ; Sun, 26 Jan 2020 22:44:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="LiZhUOIe" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AA1E2070A Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 2B3B46B0003; Sun, 26 Jan 2020 17:44:35 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 265A16B0006; Sun, 26 Jan 2020 17:44:35 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 152B36B0007; Sun, 26 Jan 2020 17:44:35 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0005.hostedemail.com [216.40.44.5]) by kanga.kvack.org (Postfix) with ESMTP id F08F46B0003 for ; Sun, 26 Jan 2020 17:44:34 -0500 (EST) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id AB63F2471 for ; Sun, 26 Jan 2020 22:44:34 +0000 (UTC) X-FDA: 76421266068.06.key39_621de3285a921 X-HE-Tag: key39_621de3285a921 X-Filterd-Recvd-Size: 4921 Received: from mail-pl1-f194.google.com (mail-pl1-f194.google.com [209.85.214.194]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Sun, 26 Jan 2020 22:44:34 +0000 (UTC) Received: by mail-pl1-f194.google.com with SMTP id q13so3065695pls.1 for ; Sun, 26 Jan 2020 14:44:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=TjEZMOqVvMiaHfNHrbmYpQxyaSRI+vukKCsubEmmQJg=; b=LiZhUOIecHLFKlKOf5LwM4AY0QJraXq2Eq6Cz5mZp25Tz4Ct5naIHG+lpYNxphSzKQ 75RjI+ggnHay5WPKmLtXxy05GkRnAgPzrxeM2eTYq6HFEjrjOWJu/m9x6pbkqD7fQOMW cQ4RExcCIJA8/9chPkONZEGXG6KNC/8JxBPjt2Nyik+qLMoIZ4x6iaIjrjQ/0RxhUmnF PTHQ8GqWkAQFZXiv8jLRjP7JQrjC6qXzIpz/Xon+MgyOPWF77OpSYfWjtd7tziFvfUjT 3mrkaCVOJTlsSI5o3TZucd+TGTlTesn54wOY08+xPnAD5ROcAHy39E7pNY63xQDZ490F n8DA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=TjEZMOqVvMiaHfNHrbmYpQxyaSRI+vukKCsubEmmQJg=; b=Lh0v2DmkETLMfC7dSksqdGVK4paXc0AU/u5KsMUsZhKbJ+x0LSmbXqAoJjuFmekZ7b HCbZO24RACgkeYLGkJ4/nlqsR4g5a8gE5VuFYK5qBYXiL4XD50daHUpKGx86z5T3G4lR sK+jFUn+wzRSIr7VU5LoCnWrJKoYmyeE8o5Gh2ypM6WrEt/lQcGx871s1T+3BdTTKvlN BxJOZEccfZBmLWgv/sqfh1q5+/koYeG3zSsNKWPWGw0mwHbHlakShOnD9JYsz9q7qugY Oh7NeV18/QcBs3POKab0XX37aV0xb0aa5M6G/OR15QTO8nFQOxEEFukP6qOYeXNAjBOV dwuA== X-Gm-Message-State: APjAAAWe3wO+nYVWlAWLUC+81LWKBuXOcS5XHU7fTStc2LJ92MA60B9p G8FaegiC/cASp9CbYCCZ75I6+fWZ8oE= X-Google-Smtp-Source: APXvYqymcVkWc2j+nwHmc4kt3i9+hl/OwHr2T5KYyyAMvu+vzhgyFwQPyThZ4nxIELGcRxsX0v/QMg== X-Received: by 2002:a17:90a:e2d4:: with SMTP id fr20mr11737424pjb.85.1580078672716; Sun, 26 Jan 2020 14:44:32 -0800 (PST) Received: from [2620:15c:17:3:3a5:23a7:5e32:4598] ([2620:15c:17:3:3a5:23a7:5e32:4598]) by smtp.gmail.com with ESMTPSA id q6sm13303717pgt.47.2020.01.26.14.44.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Jan 2020 14:44:31 -0800 (PST) Date: Sun, 26 Jan 2020 14:44:31 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Wei Yang cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] mm/vmscan.c: only adjust related kswapd cpu affinity when online cpu In-Reply-To: <20200126132052.11921-1-richardw.yang@linux.intel.com> Message-ID: References: <20200126132052.11921-1-richardw.yang@linux.intel.com> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII 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: On Sun, 26 Jan 2020, Wei Yang wrote: > When onlining a cpu, kswapd_cpu_online() is called to adjust kswapd cpu > affinity. > > Current routine does like this: > > * Iterate all the numa node > * Adjust cpu affinity when node has an online cpu > > Actually we could improve this by: > > * Just adjust the numa node to which current online cpu belongs > > Because we know which numa node the cpu belongs to and this cpu would > not affect other node. > Is there ever a situation where the cpu to be onlined would have appeared in the cpumask of another node and so a different kswapd's cpumask would now include an off-node cpu? > Signed-off-by: Wei Yang > --- > mm/vmscan.c | 19 ++++++++++--------- > 1 file changed, 10 insertions(+), 9 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 572fb17c6273..19c92d35045c 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -4049,18 +4049,19 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim) > restore their cpu bindings. */ > static int kswapd_cpu_online(unsigned int cpu) > { > - int nid; > + int nid = cpu_to_node(cpu); > + pg_data_t *pgdat; > + const struct cpumask *mask; > > - for_each_node_state(nid, N_MEMORY) { > - pg_data_t *pgdat = NODE_DATA(nid); > - const struct cpumask *mask; > + if (!node_state(nid, N_MEMORY)) > + return 0; > > - mask = cpumask_of_node(pgdat->node_id); > + pgdat = NODE_DATA(nid); > + mask = cpumask_of_node(nid); > + > + /* One of our CPUs online: restore mask */ > + set_cpus_allowed_ptr(pgdat->kswapd, mask); > > - if (cpumask_any_and(cpu_online_mask, mask) < nr_cpu_ids) > - /* One of our CPUs online: restore mask */ > - set_cpus_allowed_ptr(pgdat->kswapd, mask); > - } > return 0; > } > > -- > 2.17.1 > > >