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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4985EC433F5 for ; Fri, 17 Dec 2021 19:12:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B57C46B0071; Fri, 17 Dec 2021 14:12:41 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id AE0036B0073; Fri, 17 Dec 2021 14:12:41 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9802B6B0074; Fri, 17 Dec 2021 14:12:41 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0203.hostedemail.com [216.40.44.203]) by kanga.kvack.org (Postfix) with ESMTP id 85B136B0071 for ; Fri, 17 Dec 2021 14:12:41 -0500 (EST) Received: from smtpin02.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 425CB180CE683 for ; Fri, 17 Dec 2021 19:12:31 +0000 (UTC) X-FDA: 78928232502.02.20C45AF Received: from mail-ed1-f47.google.com (mail-ed1-f47.google.com [209.85.208.47]) by imf23.hostedemail.com (Postfix) with ESMTP id E4060140014 for ; Fri, 17 Dec 2021 19:12:25 +0000 (UTC) Received: by mail-ed1-f47.google.com with SMTP id y22so11702408edq.2 for ; Fri, 17 Dec 2021 11:12:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=mtA+D/GKcXkmGS81BrQab99wr1YM7atdDJaaJPs4yd4=; b=OAE3NSrqY7N8TDFAl/ZfWhdiOltwuyGlstIhlKoag/+sDbeTKXt5kLlhoISXOnLPPe 6ZKiOTpWvOO3kWFSrmahXXY+DYJu2x8h543xRPfRXGVSj236yIYD1Rv+SrWfwGV5wpjb haWDNTdHnAY/NbqrAdJ+ur356PVG+dAWH7pxJde5bwKXpv2UtjYUvqRTpOvCUXGOjx/l ddwPPT0O6CtClv59mBd4YZRSYZC5EJL9EXdshNhmSaDaDM8lypbIdmQNWBYuwNL3kkz+ JPGewUnb71vTWDNiNouWe4tOllZNmaPHxGLFqXc9XkjhwuzzagUN0FG98sVXM2CDQDmE tDbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=mtA+D/GKcXkmGS81BrQab99wr1YM7atdDJaaJPs4yd4=; b=Ix/BjPGJ43dAv31tUqFCtiHozPrvPGBVceGtKgA0ffMg9f1k4cVahS3H2esdZSx+Z3 YTUsU6xZDe+NQI8C/heuWKKxRLP1lxIzN9kYqBjXFtnX6ppyCum0gz9azvJ2g31hERvN tU6VkHe9DOhB063v6yMVYUuzEKqLNd8+iX1fmB9mBdyCstIqADBHeBY6neb6mSbq/lHq Q7S7oXhYPwVML7WMavgDBTR5RA3aKQNw0Q6LoZZBHGR2ug/HI3e+/6vVE5VQy5f2K6sB yYmVN9jj9vSSrUV/x+fuuLS5Em3L5NTC0xteYDk/R2ZRsp70Trgs13bPVGYV0Z99TlKQ Hppg== X-Gm-Message-State: AOAM530e7L4vfSSQQTPWRljrHLWdt+3RGv7q/yhX0TZszNY0d30rxFdU FftTZWfykauu6ymV8LULLh4yFPBuaDg7CGhVtio= X-Google-Smtp-Source: ABdhPJyrymEFaHUqSzfHGmo/atDOMQ/Ei62r4vaOWyPsPrS5v/f+Cp5Matsz3dCoqYC/uuCPuteamxm5V9/Jx/4Yt6U= X-Received: by 2002:aa7:c641:: with SMTP id z1mr742013edr.84.1639768349688; Fri, 17 Dec 2021 11:12:29 -0800 (PST) MIME-Version: 1.0 References: <20211217113049.23850-1-david@redhat.com> <20211217113049.23850-5-david@redhat.com> In-Reply-To: <20211217113049.23850-5-david@redhat.com> From: Yang Shi Date: Fri, 17 Dec 2021 11:12:17 -0800 Message-ID: Subject: Re: [PATCH v1 04/11] mm: thp: simlify total_mapcount() To: David Hildenbrand Cc: Linux Kernel Mailing List , Andrew Morton , Hugh Dickins , Linus Torvalds , David Rientjes , Shakeel Butt , John Hubbard , Jason Gunthorpe , Mike Kravetz , Mike Rapoport , "Kirill A . Shutemov" , Matthew Wilcox , Vlastimil Babka , Jann Horn , Michal Hocko , Nadav Amit , Rik van Riel , Roman Gushchin , Andrea Arcangeli , Peter Xu , Donald Dutile , Christoph Hellwig , Oleg Nesterov , Jan Kara , Linux MM , linux-kselftest@vger.kernel.org, linux-doc@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: E4060140014 X-Stat-Signature: n9afjy7yntk31c9bmimb616oepo5mrp1 Authentication-Results: imf23.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=OAE3NSrq; spf=pass (imf23.hostedemail.com: domain of shy828301@gmail.com designates 209.85.208.47 as permitted sender) smtp.mailfrom=shy828301@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-HE-Tag: 1639768345-860340 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, Dec 17, 2021 at 3:33 AM David Hildenbrand wrote: > > Let's simplify a bit, returning for PageHuge() early and using > head_compound_page() as we are only getting called for HEAD pages. > > Note the VM_BUG_ON_PAGE(PageTail(page), page) check at the beginning of > total_mapcount(). > > This is a preparation for further changes. > > Reviewed-by: Peter Xu > Signed-off-by: David Hildenbrand Reviewed-by: Yang Shi > --- > mm/huge_memory.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 4751d03947da..826cabcad11a 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -2506,12 +2506,11 @@ int total_mapcount(struct page *page) > > if (likely(!PageCompound(page))) > return atomic_read(&page->_mapcount) + 1; > + if (PageHuge(page)) > + return head_compound_mapcount(page); > > - compound = compound_mapcount(page); > nr = compound_nr(page); > - if (PageHuge(page)) > - return compound; > - ret = compound; > + ret = compound = head_compound_mapcount(page); > for (i = 0; i < nr; i++) > ret += atomic_read(&page[i]._mapcount) + 1; > /* File pages has compound_mapcount included in _mapcount */ > -- > 2.31.1 >