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=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 80CB8C2D0E4 for ; Tue, 17 Nov 2020 21:05:44 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 3F34924181 for ; Tue, 17 Nov 2020 21:05:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="M+do9ccI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F34924181 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 90F1F6B005C; Tue, 17 Nov 2020 16:05:42 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8BED86B006C; Tue, 17 Nov 2020 16:05:42 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 786556B0068; Tue, 17 Nov 2020 16:05:42 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0100.hostedemail.com [216.40.44.100]) by kanga.kvack.org (Postfix) with ESMTP id 4AA656B0036 for ; Tue, 17 Nov 2020 16:05:42 -0500 (EST) Received: from smtpin10.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id D8E688249980 for ; Tue, 17 Nov 2020 21:05:41 +0000 (UTC) X-FDA: 77495141682.10.club81_5e1511127334 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin10.hostedemail.com (Postfix) with ESMTP id 851CB16A4B1 for ; Tue, 17 Nov 2020 21:05:41 +0000 (UTC) X-HE-Tag: club81_5e1511127334 X-Filterd-Recvd-Size: 3113 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf30.hostedemail.com (Postfix) with ESMTP for ; Tue, 17 Nov 2020 21:05:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=RFeeohkz2Cx/D+vXLKhH0do1RFDw2pXSfBePcdf6Zq8=; b=M+do9ccIfreRYCvuhFX2i+cV+S Q4YXBNQDOrGUz2802V6jQ7B4IwsEKpIwiGzPwqn6UNsf8fGsARnKy+Os3eMXHnZhfsBAoSrdoriUj OcgC9DcoW6OQSsfceAFW4j10Kh0wf18h2ch+LCzNK3Hhkh3kuCeo8Ggvo6R7c9BckJWW77w7qfgtr iwr5kKaNZNpjDuybJBqrISx/L1aelBIYJEpkbH6Iuccvc2Jxy9dFJd3pOgpk1+WM9D8cblhsh68Lu WhQ2KhsOdIbCjxE+c+PZgdS40amPZJKFE6e0EIgrJGuCnFAOGFdh2ibu91sV9rfHam7wBpSDM9s+9 1YkvGVHg==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kf8AO-0003JG-DG; Tue, 17 Nov 2020 21:05:32 +0000 Date: Tue, 17 Nov 2020 21:05:32 +0000 From: Matthew Wilcox To: Roman Gushchin Cc: Zi Yan , linux-mm@kvack.org, "Kirill A . Shutemov" , Andrew Morton , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Yang Shi , Michal Hocko , John Hubbard , Ralph Campbell , David Nellans Subject: Re: [RFC PATCH 3/6] mm: page_owner: add support for splitting to any order in split page_owner. Message-ID: <20201117210532.GX29991@casper.infradead.org> References: <20201111204008.21332-1-zi.yan@sent.com> <20201111204008.21332-4-zi.yan@sent.com> <20201114001505.GA3047204@carbon.dhcp.thefacebook.com> <20201114013801.GA3069806@carbon.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201114013801.GA3069806@carbon.dhcp.thefacebook.com> 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 Fri, Nov 13, 2020 at 05:38:01PM -0800, Roman Gushchin wrote: > On Fri, Nov 13, 2020 at 08:08:58PM -0500, Zi Yan wrote: > > Matthew recently converted split_page_owner to take nr instead of order.[1] > > But I am not > > sure why, since it seems to me that two call sites (__split_huge_page in > > mm/huge_memory.c and split_page in mm/page_alloc.c) can pass the order > > information. > > Yeah, I'm not sure why too. Maybe Matthew has some input here? > You can also pass new_nr, but IMO orders look so much better here. If only I'd written that information in the changelog ... oh wait, I did! mm/page_owner: change split_page_owner to take a count The implementation of split_page_owner() prefers a count rather than the old order of the page. When we support a variable size THP, we won't have the order at this point, but we will have the number of pages. So change the interface to what the caller and callee would prefer.