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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,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 D4E54C3815B for ; Thu, 16 Apr 2020 18:26:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9D6842223D for ; Thu, 16 Apr 2020 18:26:05 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9D6842223D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4EC6B8E00DE; Thu, 16 Apr 2020 14:26:05 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 49D008E00BC; Thu, 16 Apr 2020 14:26:05 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3B2258E00DE; Thu, 16 Apr 2020 14:26:05 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0003.hostedemail.com [216.40.44.3]) by kanga.kvack.org (Postfix) with ESMTP id 1D0938E00BC for ; Thu, 16 Apr 2020 14:26:05 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id DB3785DE1 for ; Thu, 16 Apr 2020 18:26:04 +0000 (UTC) X-FDA: 76714547448.17.sort17_5216d3d91a41c X-HE-Tag: sort17_5216d3d91a41c X-Filterd-Recvd-Size: 2451 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Thu, 16 Apr 2020 18:26:03 +0000 (UTC) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R101e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e07425;MF=yang.shi@linux.alibaba.com;NM=1;PH=DS;RN=10;SR=0;TI=SMTPD_---0TvjuKXH_1587061557; Received: from US-143344MP.local(mailfrom:yang.shi@linux.alibaba.com fp:SMTPD_---0TvjuKXH_1587061557) by smtp.aliyun-inc.com(127.0.0.1); Fri, 17 Apr 2020 02:26:00 +0800 Subject: Re: [PATCHv3, RESEND 8/8] khugepaged: Introduce 'max_ptes_shared' tunable To: "Kirill A. Shutemov" Cc: "Kirill A. Shutemov" , akpm@linux-foundation.org, Andrea Arcangeli , Zi Yan , Ralph Campbell , John Hubbard , William Kucharski , linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <20200413125220.663-1-kirill.shutemov@linux.intel.com> <20200413125220.663-9-kirill.shutemov@linux.intel.com> <20200416155206.bqpd5p45oud4chg6@box> From: Yang Shi Message-ID: <33a19097-5b4f-ea6e-6d6e-3ccda56607f5@linux.alibaba.com> Date: Thu, 16 Apr 2020 11:25:56 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20200416155206.bqpd5p45oud4chg6@box> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US 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 4/16/20 8:52 AM, Kirill A. Shutemov wrote: > On Wed, Apr 15, 2020 at 02:25:30PM -0700, Yang Shi wrote: >>> @@ -595,6 +626,12 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma, >>> VM_BUG_ON_PAGE(!PageAnon(page), page); >>> + if (page_mapcount(page) > 1 && >>> + ++shared > khugepaged_max_ptes_shared) { >>> + result = SCAN_EXCEED_SHARED_PTE; >> It may be better to extract the check into a helper? For example, bool >> exceed_max_ptes_shared(struct page)? > It might be reasonable as part of wider cleanup: the same has to be done > to khugepaged_max_ptes_none and khugepaged_max_ptes_swap. > > Volunteers? :P Fine, I will take it. :-) >