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=-6.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 747C9C433E0 for ; Mon, 25 May 2020 04:59:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5332820825 for ; Mon, 25 May 2020 04:59:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=shutemov-name.20150623.gappssmtp.com header.i=@shutemov-name.20150623.gappssmtp.com header.b="ZB2bMapT" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388745AbgEYE7r (ORCPT ); Mon, 25 May 2020 00:59:47 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41482 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726649AbgEYE7q (ORCPT ); Mon, 25 May 2020 00:59:46 -0400 Received: from mail-lj1-x244.google.com (mail-lj1-x244.google.com [IPv6:2a00:1450:4864:20::244]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84994C05BD43 for ; Sun, 24 May 2020 21:59:46 -0700 (PDT) Received: by mail-lj1-x244.google.com with SMTP id m18so19320048ljo.5 for ; Sun, 24 May 2020 21:59:46 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=shutemov-name.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=+n9rUAP4H6+Zi0TTUL1JxYkv/zQYKpYIKNpCWjLtusE=; b=ZB2bMapTM0gZ3T/pJxS+tIAjDieTMBYojZ0mwW7XuuEWD+Fv+k1JtiyzD+ZqaBr9Tq lH8i3F7zAGGxPGXuTWnJm9Te/UUSV9cqtaEZZG7sQ1yVfu7pjqZXGmOZbQZ7YCEp6xBE 4fm2u6hmW3kKMvvIu51nvAPRHQ46c4IKra087+r7Va256OtaGkLjwLkOorTUxEdBsAmr XnmXf6OmMz/WmDrnKLg6gDYFWdak47KotwHkuSZCX9HSmPFcHJci0FqyN7NN5ZdCVJP0 hszBVumbnqx0pFYBFLzeidtDBQtf7eqEj0775nkJ1h0ho+RWfKdHcKpQ8ZBa7ee6WNl6 rrDQ== 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:message-id:references :mime-version:content-disposition:in-reply-to; bh=+n9rUAP4H6+Zi0TTUL1JxYkv/zQYKpYIKNpCWjLtusE=; b=Gkfxc+3GNAiT/EBQTFi1EGThWXxy6Oy9ior3qyFVfZcM9luHvD/3aPe8Jdl+/CrRhI 5KsM0uWESA8J//FvtiQokLF0iXmMqXgmgq70me54/Fnr7ZwPaPKsJtVgdIK+Zbo5+eAa ZM0G4CV+4kB+5sQvNvOkXt+WGyIUuth9HjvfPAjf9JhEOjwpM4w4NR1nE5XDFGcNMVek Wgg1W86scruHLWMnFr0mcccH1seRyz5/YuDAONQsz0y0pwngBJAEHLVrmWyW1yhE55U0 r2+M2GlUEOy9ltP8D/LqbKW1pSIIHzfV6p/vayrT4oTDlkteTM6thDZR7wYqT6sgxf7g iA3Q== X-Gm-Message-State: AOAM533KAOXPwzjdwQrM19qAOA5hGm3Sn/A0uvdA2SWHsk9Tg4J5oPD1 r3G0EN7+m0O1xWQOjMbceuwldA== X-Google-Smtp-Source: ABdhPJyCwJ2sAx2IX4iHY4LLE2cNk9uJ0NgIZnJVby3cTBD/nQ12Uvgtsyf7i4RxGbVF7B8X5BKElQ== X-Received: by 2002:a2e:9a41:: with SMTP id k1mr13615461ljj.143.1590382784839; Sun, 24 May 2020 21:59:44 -0700 (PDT) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id f5sm903566ljm.69.2020.05.24.21.59.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 24 May 2020 21:59:44 -0700 (PDT) Received: by box.localdomain (Postfix, from userid 1000) id 367BE1012E6; Mon, 25 May 2020 07:59:45 +0300 (+03) Date: Mon, 25 May 2020 07:59:45 +0300 From: "Kirill A. Shutemov" To: Matthew Wilcox Cc: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v4 24/36] mm: Remove page fault assumption of compound page size Message-ID: <20200525045945.lkw36jergxwg7bfj@box> References: <20200515131656.12890-1-willy@infradead.org> <20200515131656.12890-25-willy@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200515131656.12890-25-willy@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, May 15, 2020 at 06:16:44AM -0700, Matthew Wilcox wrote: > From: "Matthew Wilcox (Oracle)" > > A compound page in the page cache will not necessarily be of PMD size, > so check explicitly. > > Signed-off-by: Matthew Wilcox (Oracle) > --- > mm/memory.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index f703fe8c8346..d68ce428ddd2 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3549,13 +3549,14 @@ static vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page) > unsigned long haddr = vmf->address & HPAGE_PMD_MASK; > pmd_t entry; > int i; > - vm_fault_t ret; > + vm_fault_t ret = VM_FAULT_FALLBACK; > > if (!transhuge_vma_suitable(vma, haddr)) > - return VM_FAULT_FALLBACK; > + return ret; > > - ret = VM_FAULT_FALLBACK; > page = compound_head(page); > + if (page_order(page) != HPAGE_PMD_ORDER) > + return ret; Maybe WARN() for page_order(page) > HPAGE_PMD_ORDER. It would be fun to handle :P > > /* > * Archs like ppc64 need additonal space to store information > -- > 2.26.2 > -- Kirill A. Shutemov