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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,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 53FB9C432C0 for ; Fri, 22 Nov 2019 10:03:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 245FC20707 for ; Fri, 22 Nov 2019 10:03:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="FdpLtI8r" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726865AbfKVKDl (ORCPT ); Fri, 22 Nov 2019 05:03:41 -0500 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:28152 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726526AbfKVKDl (ORCPT ); Fri, 22 Nov 2019 05:03:41 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1574417020; h=from:from: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=ZZxSBnToU8Q+4liQ4absw6sZ2OBAyuvw5i8iX6n4XC4=; b=FdpLtI8raAPZqHD/7rt6JwytG4uObC+jOGIZ9je2lAgBGKe9e5bEV0526qvxXMRZtJ77O5 ZbBp4Z53zxgwKMF9UnDJUsGcAplYYT6zysLrfJEjzvzGlTKnhQPJNtL4/dY1Pm82F1N3jV BQ7tUYdhjy2wHwvyVhZd2Df2Qj0kOG8= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-309-NFZgtFxTMoCPeqWMEtUm5Q-1; Fri, 22 Nov 2019 05:03:37 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 70EC2801E5D; Fri, 22 Nov 2019 10:03:34 +0000 (UTC) Received: from [10.36.118.121] (unknown [10.36.118.121]) by smtp.corp.redhat.com (Postfix) with ESMTP id 10CF110372C0; Fri, 22 Nov 2019 10:03:30 +0000 (UTC) Subject: Re: [RFC v1 00/19] Modify zonelist to nodelist v1 To: Pengfei Li , akpm@linux-foundation.org Cc: mgorman@techsingularity.net, mhocko@kernel.org, vbabka@suse.cz, cl@linux.com, iamjoonsoo.kim@lge.com, guro@fb.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20191121151811.49742-1-fly@kernel.page> From: David Hildenbrand Organization: Red Hat GmbH Message-ID: <1bb37491-72a7-feaa-722d-a5825813a409@redhat.com> Date: Fri, 22 Nov 2019 11:03:30 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191121151811.49742-1-fly@kernel.page> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: NFZgtFxTMoCPeqWMEtUm5Q-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 21.11.19 16:17, Pengfei Li wrote: > Motivation > ---------- > Currently if we want to iterate through all the nodes we have to > traverse all the zones from the zonelist. >=20 > So in order to reduce the number of loops required to traverse node, > this series of patches modified the zonelist to nodelist. >=20 > Two new macros have been introduced: > 1) for_each_node_nlist > 2) for_each_node_nlist_nodemask >=20 >=20 > Benefit > ------- > 1. For a NUMA system with N nodes, each node has M zones, the number > of loops is reduced from N*M times to N times when traversing node. >=20 > 2. The size of pg_data_t is much reduced. >=20 >=20 > Test Result > ----------- > Currently I have only performed a simple page allocation benchmark > test on my laptop, and the results show that the performance of a > system with only one node is almost unaffected. >=20 So you are seeing no performance changes. I am wondering why do we need=20 this, then - because your motivation sounds like a performance=20 improvement? (not completely against this, just trying to understand the=20 value of this :) ) --=20 Thanks, David / dhildenb