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=-12.9 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=ham 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 71ADCC33CAF for ; Sun, 19 Jan 2020 22:14:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3A6C620678 for ; Sun, 19 Jan 2020 22:14:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="bUCtznLA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728855AbgASWOb (ORCPT ); Sun, 19 Jan 2020 17:14:31 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:40837 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728655AbgASWOb (ORCPT ); Sun, 19 Jan 2020 17:14:31 -0500 Received: by mail-pl1-f193.google.com with SMTP id s21so12294780plr.7 for ; Sun, 19 Jan 2020 14:14:30 -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=Bo0KESN/+oMc2MKezmCpLg4ifpNjJnDe1/TBk2evDpo=; b=bUCtznLA6/j1T5gjcFIAJ/ZuMb2KciubPpHzQvVIY48jBehXIICamCp129OskbMcMG h3BPTAf3Y5ounKddTHTdboV/chzH3cmlidwO7WFi9Bzi0Rf3AhCxfk0YLJRUbRkCZZ93 DJ0gol/OfmquqIAi2lhDaZYKyjTYe7YWAhSuzaMPhkV8ULWcbBkUhl71F3g8tjCOgugZ OqQuhmJtQrkxA85e3lZ09TBLQT9nGhIp7OT3vknxNETGvYPqvVdCBlck+HdSl+PHsuBV 9eu6MKr+f66ryY9QEh+rL4btBNPauXw15gjuloAJ3sWG3rmfxc40q5AyCQJ/ugXLVFpQ TLbA== 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=Bo0KESN/+oMc2MKezmCpLg4ifpNjJnDe1/TBk2evDpo=; b=CT0zlvLT1SZccI/IY5FY7E7ej4fIM22FVIY6igDL55r+NeIvhSVL3DuN8JfkA8bwTy z1fbCnLR36kAhXeAIV4eTUMAo/GpYusErIGyAKQ2uf4d9j5hI3BFvIN2Asc1Pi8bkFVh 5rRwNDOGlalzOXK6imBEudC+2GiFQ7Mh+ANwmlZ1L+SEMb0BJnpmyu5lYmqIgpeNtTVL L8flzDMSs4QGiYg5av/6KGSvH/qIL9H95jTY935iwSXUdvFAyAwAwZIlYkMTIYDfgA61 hQM7ki3motrHgbNgcmjKFCfeRN2Oyqtwc0ghGXq1x9RT9LmeXyluo8bAzSSV5XiVgDUm GRWQ== X-Gm-Message-State: APjAAAXFZ1O6LOM5IzBeDCSsCsRZKeDwbfgZcG0rtRMnB15uWdUhG1DT lzL6DSwc1nxPxWzWzrMfeD4zCg== X-Google-Smtp-Source: APXvYqzsc1ebgRP87A/33MVeOw0cciLy5LulWI6KoHB0TBKFhM9NxgevSezrm/R48Q+8z8TOgkmtiA== X-Received: by 2002:a17:90a:c301:: with SMTP id g1mr19741926pjt.88.1579472069981; Sun, 19 Jan 2020 14:14:29 -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 n4sm34595568pgg.88.2020.01.19.14.14.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 19 Jan 2020 14:14:29 -0800 (PST) Date: Sun, 19 Jan 2020 14:14:28 -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, mhocko@suse.com, yang.shi@linux.alibaba.com Subject: Re: [PATCH 2/8] mm/migrate.c: not necessary to check start and i In-Reply-To: <20200119030636.11899-3-richardw.yang@linux.intel.com> Message-ID: References: <20200119030636.11899-1-richardw.yang@linux.intel.com> <20200119030636.11899-3-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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 19 Jan 2020, Wei Yang wrote: > diff --git a/mm/migrate.c b/mm/migrate.c > index ba7cf4fa43a0..c3ef70de5876 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -1664,11 +1664,9 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, > err = do_move_pages_to_node(mm, &pagelist, current_node); > if (err) > goto out; > - if (i > start) { > - err = store_status(status, start, current_node, i - start); > - if (err) > - goto out; > - } > + err = store_status(status, start, current_node, i - start); > + if (err) > + goto out; > current_node = NUMA_NO_NODE; > } > out_flush: Not sure this is useful, it relies on the implementation of store_status() when i == start and the overhead of the function call should actually be slower than the simple conditional to avoid it in that case?