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 B6C69C433F5 for ; Tue, 19 Apr 2022 15:13:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B04808D0077; Tue, 19 Apr 2022 11:13:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AB2318D0047; Tue, 19 Apr 2022 11:13:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9533D8D0077; Tue, 19 Apr 2022 11:13:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.hostedemail.com [64.99.140.28]) by kanga.kvack.org (Postfix) with ESMTP id 865818D0047 for ; Tue, 19 Apr 2022 11:13:52 -0400 (EDT) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 4AA3C225EA for ; Tue, 19 Apr 2022 15:13:52 +0000 (UTC) X-FDA: 79373973504.14.C1ACAC3 Received: from mail-qt1-f177.google.com (mail-qt1-f177.google.com [209.85.160.177]) by imf05.hostedemail.com (Postfix) with ESMTP id 8FE78100013 for ; Tue, 19 Apr 2022 15:13:50 +0000 (UTC) Received: by mail-qt1-f177.google.com with SMTP id z19so12405010qtw.2 for ; Tue, 19 Apr 2022 08:13:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cmpxchg-org.20210112.gappssmtp.com; s=20210112; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=cBtrsK5BvMDys085W5coB5UFTML9DXLGcwarLFdTr3s=; b=uNNJ8Vq9kLmQc9I+6Hgo6a2ttNR/7rcwjnrlxgZh6WP66D8Gl96P+FCvWk5GaltbbE 4086gsTDO1o5RLq/N4Tv//kIfyJHCkPGe9LgS4iJXKUXdolvMUsbPTA9kYeHQdMNG0EX pPUt9kp8AogyIQr0MazUTRtYVQ7Z2wicZP9Kfw9mbu0mGGAR90juLeEs51pfla/rYxWD 7aEQRgndZzWlUxk6mh8fwTkwLzMyg9qoAgU44Bu3afhetoHhulQ9FHLS2U3cM/iyr4aF 5aJBW7PjppKpZ5aO6zIEd7Q9bZRGoZNNqqdofEjvMD2KhdTvJS1PYeG4iJpj0Gn6D5VW HiNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=cBtrsK5BvMDys085W5coB5UFTML9DXLGcwarLFdTr3s=; b=E/cFuDiUplfP3Qc44hKPEmHKthF9CzbaEh3mbUZ3fC+Y3iVY5BeU+RTg/TDfnsu6me cpZunpL6AOmAREsPKSMZFq5kwYZwozP4J4Pgkb2HrM1LJmLJL3E+o4NfEBkTIQ4HsiS0 Xztre1YcFUKt3DHqnAFIAPVUHfTmYKh5OGGZRwnjHH6VY6OL8QMhZfnx9IoiiCWNPqmp +abAemA+Cgeubtp4REu/OK7hnxxwxUsbs3slRj81aYbp/UsUqxG1LeqK7zIRmROH5rD2 5XY4xqexd4jMSciAcgDVg2PGigApaD+ZA9w+oXJ4n8N6vcek5aRhJN38gZmRgd9QSJ50 r7Gg== X-Gm-Message-State: AOAM5325J73h7CqJegZYdDt9oXQCnvw9MPW7dOZ6Z/ArSJXg561SQE3p hF0NSbcIw6HHROrA4Zj26d8TNw== X-Google-Smtp-Source: ABdhPJyQ7rJ74CQW1DHqBcmn1unezi1go+9dabDzf1fmtoet8jUZ2oPJDPi1cbfuHLGQ2XaZaegAQA== X-Received: by 2002:a05:622a:10d:b0:2f1:d7bb:dd2b with SMTP id u13-20020a05622a010d00b002f1d7bbdd2bmr10773928qtw.90.1650381230159; Tue, 19 Apr 2022 08:13:50 -0700 (PDT) Received: from localhost (cpe-98-15-154-102.hvc.res.rr.com. [98.15.154.102]) by smtp.gmail.com with ESMTPSA id i19-20020ac85c13000000b002f33d140da9sm180196qti.20.2022.04.19.08.13.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 19 Apr 2022 08:13:49 -0700 (PDT) Date: Tue, 19 Apr 2022 11:13:48 -0400 From: Johannes Weiner To: Peter Xu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, Mike Kravetz , Nadav Amit , Matthew Wilcox , Mike Rapoport , David Hildenbrand , Hugh Dickins , Jerome Glisse , "Kirill A . Shutemov" , Andrea Arcangeli , Andrew Morton , Axel Rasmussen , Alistair Popple Subject: Re: [PATCH v8 22/23] mm: Enable PTE markers by default Message-ID: References: <20220405014646.13522-1-peterx@redhat.com> <20220405014929.15158-1-peterx@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220405014929.15158-1-peterx@redhat.com> Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=cmpxchg-org.20210112.gappssmtp.com header.s=20210112 header.b=uNNJ8Vq9; spf=pass (imf05.hostedemail.com: domain of hannes@cmpxchg.org designates 209.85.160.177 as permitted sender) smtp.mailfrom=hannes@cmpxchg.org; dmarc=pass (policy=none) header.from=cmpxchg.org X-Stat-Signature: fzmfhs1a6yxfdaetnhjq6pttihufcxz5 X-Rspamd-Queue-Id: 8FE78100013 X-Rspamd-Server: rspam04 X-Rspam-User: X-HE-Tag: 1650381230-477939 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: Hi Peter, On Mon, Apr 04, 2022 at 09:49:29PM -0400, Peter Xu wrote: > Enable PTE markers by default. On x86_64 it means it'll auto-enable > PTE_MARKER_UFFD_WP as well. > > Signed-off-by: Peter Xu > --- > mm/Kconfig | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/mm/Kconfig b/mm/Kconfig > index 6e7c2d59fa96..3eca34c864c5 100644 > --- a/mm/Kconfig > +++ b/mm/Kconfig > @@ -911,12 +911,14 @@ config ANON_VMA_NAME > > config PTE_MARKER > bool "Marker PTEs support" > + default y > > help > Allows to create marker PTEs for file-backed memory. make oldconfig just prompted me on these: --- Marker PTEs support (PTE_MARKER) [Y/n/?] (NEW) ? CONFIG_PTE_MARKER: Allows to create marker PTEs for file-backed memory. Symbol: PTE_MARKER [=y] Type : bool Defined at mm/Kconfig:1046 Prompt: Marker PTEs support Location: Main menu -> Memory Management options --- > config PTE_MARKER_UFFD_WP > bool "Marker PTEs support for userfaultfd write protection" > + default y > depends on PTE_MARKER && HAVE_ARCH_USERFAULTFD_WP It's not possible to answer them without looking at the code. But after looking at the code, I'm still not sure why it asks me. Isn't this infrastructure code? Wouldn't it make more sense to remove the prompt string and have userfaultfd simply select those? If this is too experimental to enable per default, a more reasonable question for the user would be a "userfaultfd file support" option or something, and have *that* select the marker code. Thanks!