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=-8.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham 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 989DCC433DB for ; Mon, 11 Jan 2021 14:25:32 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 437B622473 for ; Mon, 11 Jan 2021 14:25:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 437B622473 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=shutemov.name Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9C9B38D0031; Mon, 11 Jan 2021 09:25:31 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 97A5F8D0020; Mon, 11 Jan 2021 09:25:31 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 891C88D0031; Mon, 11 Jan 2021 09:25:31 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0034.hostedemail.com [216.40.44.34]) by kanga.kvack.org (Postfix) with ESMTP id 734038D0020 for ; Mon, 11 Jan 2021 09:25:31 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 152B9181AEF00 for ; Mon, 11 Jan 2021 14:25:31 +0000 (UTC) X-FDA: 77693717262.12.step65_5c0bb502750d Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin12.hostedemail.com (Postfix) with ESMTP id C561718014B80 for ; Mon, 11 Jan 2021 14:25:30 +0000 (UTC) X-HE-Tag: step65_5c0bb502750d X-Filterd-Recvd-Size: 4103 Received: from mail-lf1-f45.google.com (mail-lf1-f45.google.com [209.85.167.45]) by imf34.hostedemail.com (Postfix) with ESMTP for ; Mon, 11 Jan 2021 14:25:30 +0000 (UTC) Received: by mail-lf1-f45.google.com with SMTP id b26so37967965lff.9 for ; Mon, 11 Jan 2021 06:25:30 -0800 (PST) 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=smCy1Yjkgz+gZDtvnre1/QglxuwwJh77VQyDG7f7TRE=; b=ZUuH8XyUNwUDj/ax6jtLuay1zUfAHTmdAj5OEzyXghQZcVky5ep8DZqIxsMBY2n40g c06X17Dy/0BohuoUCgTPEfnF1EKIHFZ+Uin5pZQVE8W7Zie1OKBDts7Fw6CAJ8oUkF0+ r/h5M78XOTQOyOFRvsAhMPXJIxAmIhjxGdlOX9Hi3+nX64JjFSDQLgrhZZq82sDae6ST Awd6jayAfyX09bC+vlJFcEgIfQybESEifE9Tuf2F/hjEouxgD3ozygW24IF04Z8y8ynU N9j5pf85cu+j4nquHHa/0nuHULcDcB/q8AmB2mg3d0OdxGBUSWwN2TzUtKlGvU/bY+eL /P7g== 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=smCy1Yjkgz+gZDtvnre1/QglxuwwJh77VQyDG7f7TRE=; b=a9SHCBZmUiMNM0RVJVUBT+nGuNIhGKoqGYuwlc82pkDHR8Dq5FzixYuBknipcNoNgH yr/7z7XI+k/H1dxqIIgGa+H/t3hra1HBVY4xBJuGAobzfiYHXPRavNAU0rx3g1x3yFkz TInzQpQxpioa2W9rfjl7zSqMWtQ+MjhiW0HLzb7SsnT9yBCOFt9x581rBp8opyCO4/4N oXyazLySPc1vf/U0fHaoCZ6jGTKLgStI7bL5ef1zBIn6uCYbIUZybCueiPooANypMY0o s78aiwu52kOdzyqGWv+9dlWjYsqChRhaLtxaA2oz7gz81lSzjdxnN03/EmDQGwYooAHh L5OQ== X-Gm-Message-State: AOAM533d951zHJQEXAFFJlawpaD1t5rm2JUkGqCxiACl8kiAW/jxjCXb wZHHwiu93BqYe8SOi6P7qnwm1g== X-Google-Smtp-Source: ABdhPJyUEIHi1OeJLqcYRsOQdNKTnpdC0urVnyRPLnSVMvyEGUufCwFJNYt2YI+Kmx+uW4swx/YObw== X-Received: by 2002:a19:f601:: with SMTP id x1mr7048733lfe.256.1610375129044; Mon, 11 Jan 2021 06:25:29 -0800 (PST) Received: from box.localdomain ([86.57.175.117]) by smtp.gmail.com with ESMTPSA id b7sm3440379ljf.76.2021.01.11.06.25.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Jan 2021 06:25:28 -0800 (PST) Received: by box.localdomain (Postfix, from userid 1000) id B18BE102238; Mon, 11 Jan 2021 17:25:33 +0300 (+03) Date: Mon, 11 Jan 2021 17:25:33 +0300 From: "Kirill A. Shutemov" To: Will Deacon Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Catalin Marinas , Jan Kara , Minchan Kim , Andrew Morton , "Kirill A . Shutemov" , Linus Torvalds , Vinayak Menon , Hugh Dickins , kernel-team@android.com Subject: Re: [PATCH v2 2/3] mm: Allow architectures to request 'old' entries when prefaulting Message-ID: <20210111142533.oulduqd76mkpdkst@box> References: <20210108171517.5290-1-will@kernel.org> <20210108171517.5290-3-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210108171517.5290-3-will@kernel.org> 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, Jan 08, 2021 at 05:15:16PM +0000, Will Deacon wrote: > diff --git a/mm/filemap.c b/mm/filemap.c > index c1f2dc89b8a7..0fb9d1714797 100644 > --- a/mm/filemap.c > +++ b/mm/filemap.c > @@ -3051,14 +3051,18 @@ vm_fault_t filemap_map_pages(struct vm_fault *vmf, > if (!pte_none(*vmf->pte)) > goto unlock; > > + /* We're about to handle the fault */ > + if (vmf->address == address) { > + vmf->flags &= ~FAULT_FLAG_PREFAULT; > + ret = VM_FAULT_NOPAGE; > + } else { > + vmf->flags |= FAULT_FLAG_PREFAULT; > + } > + Do we need to restore the oririnal status of the bit once we are done? -- Kirill A. Shutemov