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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 995D2ECE58C for ; Wed, 9 Oct 2019 17:03:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6F1FD218AC for ; Wed, 9 Oct 2019 17:03:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=shipmail.org header.i=@shipmail.org header.b="au2vnm4n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731881AbfJIRDa (ORCPT ); Wed, 9 Oct 2019 13:03:30 -0400 Received: from ste-pvt-msa2.bahnhof.se ([213.80.101.71]:60125 "EHLO ste-pvt-msa2.bahnhof.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730546AbfJIRD3 (ORCPT ); Wed, 9 Oct 2019 13:03:29 -0400 Received: from localhost (localhost [127.0.0.1]) by ste-pvt-msa2.bahnhof.se (Postfix) with ESMTP id 7BB7F3F99B; Wed, 9 Oct 2019 19:03:27 +0200 (CEST) Authentication-Results: ste-pvt-msa2.bahnhof.se; dkim=pass (1024-bit key; unprotected) header.d=shipmail.org header.i=@shipmail.org header.b=au2vnm4n; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at bahnhof.se Authentication-Results: ste-ftg-msa2.bahnhof.se (amavisd-new); dkim=pass (1024-bit key) header.d=shipmail.org Received: from ste-pvt-msa2.bahnhof.se ([127.0.0.1]) by localhost (ste-ftg-msa2.bahnhof.se [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id HTYE5enBQACG; Wed, 9 Oct 2019 19:03:26 +0200 (CEST) Received: from mail1.shipmail.org (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) (Authenticated sender: mb878879) by ste-pvt-msa2.bahnhof.se (Postfix) with ESMTPA id 727FD3F92C; Wed, 9 Oct 2019 19:03:25 +0200 (CEST) Received: from localhost.localdomain (h-205-35.A357.priv.bahnhof.se [155.4.205.35]) by mail1.shipmail.org (Postfix) with ESMTPSA id 0319936016C; Wed, 9 Oct 2019 19:03:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=shipmail.org; s=mail; t=1570640605; bh=ZTdGBetgktrXJR2odbaAV4HXWOuZWP+ZPKCFryblwi8=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=au2vnm4n62gXuapIh87b7KtGUtJPWjvf1Fm8hTpSvSwF5y0ULh4L86XYGCvt0TiES jtsWHdnaYg9MaIU66VBDM8iWaI8zPDeJMb/ZeUWJsg75y2mdADsX7aG90yuk5DfIIp QvGpxTEc6tz23XhEbpZJjlMWkVytVtIFtFYRBdvU= Subject: Re: [PATCH v4 3/9] mm: pagewalk: Don't split transhuge pmds when a pmd_entry is present To: Linus Torvalds , "Kirill A. Shutemov" Cc: Linux Kernel Mailing List , Linux-MM , Thomas Hellstrom , Matthew Wilcox , Will Deacon , Peter Zijlstra , Rik van Riel , Minchan Kim , Michal Hocko , Huang Ying , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= References: <20191008091508.2682-1-thomas_os@shipmail.org> <20191008091508.2682-4-thomas_os@shipmail.org> <20191009152737.p42w7w456zklxz72@box> From: =?UTF-8?Q?Thomas_Hellstr=c3=b6m_=28VMware=29?= Organization: VMware Inc. Message-ID: <03d85a6a-e24a-82f4-93b8-86584b463471@shipmail.org> Date: Wed, 9 Oct 2019 19:03:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/9/19 6:21 PM, Linus Torvalds wrote: > On Wed, Oct 9, 2019 at 8:27 AM Kirill A. Shutemov wrote: >> Do we have any current user that expect split_huge_pmd() in this scenario. > No. There are no current users of the pmd callback and the pte > callback at all, that I could find. > > But it looks like the new drm use does want a "I can't handle the > hugepage, please split it and I'll fo the ptes instead". > Nope, it handles the hugepages by ignoring them, since they should be read-only, but if pmd_entry() was called with something else than a hugepage, then it requests the fallback, but never a split. /Thomas