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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 422FFC83003 for ; Thu, 2 Mar 2023 22:01:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229697AbjCBWB3 (ORCPT ); Thu, 2 Mar 2023 17:01:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43862 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229614AbjCBWBW (ORCPT ); Thu, 2 Mar 2023 17:01:22 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 47EEC5A6E1 for ; Thu, 2 Mar 2023 14:00:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1677794423; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zpF+61RhbjBED9gh9OlDPVvD+1GeHmY73K8Lmm1HO1w=; b=Z95kFgtdGfyhOqfPmAxmrn79PNMq0gCems5a1QG8QMEernV/EsnzJRgaMKiHIy+Qr1+aCb f8h1l+d/MN8gxJg5bORvfeAfVzvwkV6L5v3f+rJ8PWKc6OyBGSiGKNoW151OIpivCH/MfK iWeyQz7fY87neaaEJFhujIZ9Wjw2pyc= Received: from mail-qt1-f199.google.com (mail-qt1-f199.google.com [209.85.160.199]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-82-YRKvC3e9PgqHyB-PYBl1sw-1; Thu, 02 Mar 2023 17:00:21 -0500 X-MC-Unique: YRKvC3e9PgqHyB-PYBl1sw-1 Received: by mail-qt1-f199.google.com with SMTP id c5-20020ac85185000000b003bfae3b8051so452598qtn.0 for ; Thu, 02 Mar 2023 14:00:21 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1677794420; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=zpF+61RhbjBED9gh9OlDPVvD+1GeHmY73K8Lmm1HO1w=; b=zF1pESBVMbulSjvI7ob07YlktAWBnBzy1V09DC4bKbLCr35ANDGnf+eP1g8a7s10jX 3SvJWk/Rkm8H7W2nvTZAz22yU1xhiEEgs6aqkrfg/mtvhC0GgWZeWoIj46LyB1GKMs+/ MmKDkW547IRvvfxPyLXEC7Y3hKyAHMysWD6ek+BFjqUssLC3gpiwuWlq1skGytqUf03l rr+4rr6T0rWSkPKsoMe1EioGTqzedc2GwzjbZeBG4Ep+0Y+gExJwcs7eQ39XbA4xv6xn 7LMtB0tixZzgSevgMrD87jeMlEWNHD+IVHnJaGOH7/eJ0NZuHs0Gj3aePxUEpeOGzXhd eusg== X-Gm-Message-State: AO0yUKXArSk3PbxqBVx3gf+GZqCOiM029AEWDMrbAk4MuzCNpUrqhCNm Gs3vK/hZu89BVEQ+1Re94hefHvJpFg1fjPJZWvv7x2F+BQCB7GhmHvAwPi1Dvsml2WV+9Sv19rO 46lmKxJQgKcnxQBlY/MG8i2J3 X-Received: by 2002:ac8:580f:0:b0:3bf:daa8:cacc with SMTP id g15-20020ac8580f000000b003bfdaa8caccmr22832383qtg.3.1677794420495; Thu, 02 Mar 2023 14:00:20 -0800 (PST) X-Google-Smtp-Source: AK7set+Dd+YGqo/SioYo2gFqWFziGqP77BVBRsHhvTjzMkmzleJIrVboVo66FWVtVnDVZtABxKAS4w== X-Received: by 2002:ac8:580f:0:b0:3bf:daa8:cacc with SMTP id g15-20020ac8580f000000b003bfdaa8caccmr22832326qtg.3.1677794420075; Thu, 02 Mar 2023 14:00:20 -0800 (PST) Received: from x1n (bras-base-aurron9127w-grc-56-70-30-145-63.dsl.bell.ca. [70.30.145.63]) by smtp.gmail.com with ESMTPSA id a191-20020ae9e8c8000000b007423843d879sm427457qkg.93.2023.03.02.14.00.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 02 Mar 2023 14:00:19 -0800 (PST) Date: Thu, 2 Mar 2023 17:00:18 -0500 From: Peter Xu To: Muhammad Usama Anjum Cc: David Hildenbrand , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrea Arcangeli , Andrew Morton , Mike Rapoport , Axel Rasmussen , Nadav Amit , "kernel@collabora.com" Subject: Re: [PATCH v2] mm/uffd: UFFD_FEATURE_WP_UNPOPULATED Message-ID: References: <640319be-ddb6-d74f-b731-eee5ceab3d01@collabora.com> <8783f47e-76ea-cd24-e373-f2156884cd05@redhat.com> <982c1623-ac28-2743-d6a3-4faf42f72d47@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 02, 2023 at 08:14:05PM +0500, Muhammad Usama Anjum wrote: > I've heard about a use case where a file of size 10s of GBs can be mapped > to the memory and then accessed off and on. We need to handle this > correctly and efficiently. Note again that besides any slowness it'll stop working for generic FSs. One way is we can consider enabling uffd-wp async for all archs, but I need to think more about it, and it will not be compatible with any other modes. -- Peter Xu