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 5505CC433EF for ; Wed, 9 Mar 2022 22:49:06 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D2F668D0002; Wed, 9 Mar 2022 17:49:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id CDE018D0001; Wed, 9 Mar 2022 17:49:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B7F2B8D0002; Wed, 9 Mar 2022 17:49:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.27]) by kanga.kvack.org (Postfix) with ESMTP id A5CAD8D0001 for ; Wed, 9 Mar 2022 17:49:05 -0500 (EST) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 81D2723D46 for ; Wed, 9 Mar 2022 22:49:05 +0000 (UTC) X-FDA: 79226339850.05.B704887 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) by imf12.hostedemail.com (Postfix) with ESMTP id 1379940009 for ; Wed, 9 Mar 2022 22:49:04 +0000 (UTC) Received: by mail-pl1-f172.google.com with SMTP id h5so1879748plf.7 for ; Wed, 09 Mar 2022 14:49:04 -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=b8sGPodv03lURDs+UTCmJTXbinqTazBj7GzO19WGdj8=; b=oVw5DjrUJJwEl6YOtLvJQFhFGdu/0vnrbZHNBEOmG/BzRuJQVkFaV5k2i0mdx8t2VP KC0Y7zW4Gw2aPMu7XFg5MPFyzr6WOndyiKvc3PggTVBJ67qhHYLjibAhGI5PRcpGQ4m9 bbNh6jviHh324A+1bBKVGy/sV+VWd44ZGzMEv3Q1uAJx0RXNCwOy/cXUZQtJ0r3+BwKp UOn0ddLgcgKimyvUn+5wKf1rOiRoqszmU+F7n8AqIdrvQ2FHRpRDd+thjRPtOV3FJYP2 GjAtF34WD7+4QDAP0wT3hsy54+2qcPPXMHMbI9eXidrGuLAhk219spqTgeRFmCJe/5/c W6Ag== 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=b8sGPodv03lURDs+UTCmJTXbinqTazBj7GzO19WGdj8=; b=Z56OKcGAmDJPJmlIbsAQhdg48WYCzJbPFAIICzBt8Twoms1P7k/lY7OAV7eI9A1gpt c/hBmfSruDuVY9kliBrbNNVXnmarA3oTdts/0BtXNt4IoPfJCg62OvPw+O8QezQNFo7V n6V6dL8ZsFUZw8Kuv+1S3V5Xxawk5qbJ+7jJ3S5FH8aPzeZ1BWO9XncBrSVDFBovyXQN CrMRPBaV6JqHOQj/l65HXSbFUCYpCit2qngLEmrezlk15YYHocHTyycdd8wsigJZpz5I N/HjTa9b156Zfr+XgwW3cpcoy3i9CfpYHSPLJpNOzN0Csfi3hZ01GXmIQOXU6AY7QbZh OuMQ== X-Gm-Message-State: AOAM533akXjwTi63H283Ynl/htT0uosUeGo63lZnEXeoXlxCY02WOif+ 7HEXO6eipadrM7mRbQAF0h8kMAdycgKaXSm5jIk= X-Google-Smtp-Source: ABdhPJyYCLEsCgjmqepKfitO7iSEZ2sF0tzRWmyfBvekmYdQ/YRAEnN3RA2x801BC4vny85FPscjhnsJHpGRqGpYeUk= X-Received: by 2002:a17:903:124a:b0:151:99fe:1a10 with SMTP id u10-20020a170903124a00b0015199fe1a10mr1803374plh.87.1646866144013; Wed, 09 Mar 2022 14:49:04 -0800 (PST) MIME-Version: 1.0 References: <20220308213417.1407042-1-zokeefe@google.com> <20220308213417.1407042-2-zokeefe@google.com> In-Reply-To: <20220308213417.1407042-2-zokeefe@google.com> From: Yang Shi Date: Wed, 9 Mar 2022 14:48:52 -0800 Message-ID: Subject: Re: [RFC PATCH 01/14] mm/rmap: add mm_find_pmd_raw helper To: "Zach O'Keefe" Cc: Alex Shi , David Hildenbrand , David Rientjes , Michal Hocko , Pasha Tatashin , SeongJae Park , Song Liu , Vlastimil Babka , Zi Yan , Linux MM , Andrea Arcangeli , Andrew Morton , Arnd Bergmann , Axel Rasmussen , Chris Kennelly , Chris Zankel , Helge Deller , Hugh Dickins , Ivan Kokshaysky , "James E.J. Bottomley" , Jens Axboe , "Kirill A. Shutemov" , Matthew Wilcox , Matt Turner , Max Filippov , Miaohe Lin , Minchan Kim , Patrick Xia , Pavel Begunkov , Peter Xu , Richard Henderson , Thomas Bogendoerfer Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 1379940009 X-Stat-Signature: fkw3otkgo1sx3f3ah18z33xjsghpw6am Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=oVw5DjrU; spf=pass (imf12.hostedemail.com: domain of shy828301@gmail.com designates 209.85.214.172 as permitted sender) smtp.mailfrom=shy828301@gmail.com; dmarc=pass (policy=none) header.from=gmail.com X-Rspam-User: X-HE-Tag: 1646866144-660895 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 Tue, Mar 8, 2022 at 1:34 PM Zach O'Keefe wrote: > > Later in the series, we want to find a pmd and take different actions, > depending on if the pmd maps a thp or not. Currently, mm_find_pmd() > returns NULL if a valid pmd maps a thp, and so we can't use it directly. > > Split mm_find_pmd() into 2 parts: mm_find_pmd_raw(), which returns a > raw pmd pointer, and the logic that filters out non-present none, or > huge pmds. mm_find_pmd_raw() can then be reused later in the series. > > Signed-off-by: Zach O'Keefe > --- > mm/internal.h | 1 + > mm/rmap.c | 15 +++++++++++++-- > 2 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/mm/internal.h b/mm/internal.h > index 86277d90a5e2..aaea25bb9096 100644 > --- a/mm/internal.h > +++ b/mm/internal.h > @@ -166,6 +166,7 @@ extern void reclaim_throttle(pg_data_t *pgdat, enum vmscan_throttle_state reason > /* > * in mm/rmap.c: > */ > +pmd_t *mm_find_pmd_raw(struct mm_struct *mm, unsigned long address); > extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address); > > /* > diff --git a/mm/rmap.c b/mm/rmap.c > index 70375c331083..0ae99affcb27 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -758,13 +758,12 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma) > return vma_address(page, vma); > } > > -pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address) > +pmd_t *mm_find_pmd_raw(struct mm_struct *mm, unsigned long address) Typically we have the new helper and the users in the same patch. It would make the review easier. > { > pgd_t *pgd; > p4d_t *p4d; > pud_t *pud; > pmd_t *pmd = NULL; > - pmd_t pmde; > > pgd = pgd_offset(mm, address); > if (!pgd_present(*pgd)) > @@ -779,6 +778,18 @@ pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address) > goto out; > > pmd = pmd_offset(pud, address); > +out: > + return pmd; > +} > + > +pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address) > +{ > + pmd_t pmde; > + pmd_t *pmd; > + > + pmd = mm_find_pmd_raw(mm, address); > + if (!pmd) > + goto out; > /* > * Some THP functions use the sequence pmdp_huge_clear_flush(), set_pmd_at() > * without holding anon_vma lock for write. So when looking for a > -- > 2.35.1.616.g0bdcbb4464-goog >