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 2BBB7C61DA4 for ; Mon, 30 Jan 2023 09:10:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236092AbjA3JK3 (ORCPT ); Mon, 30 Jan 2023 04:10:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235594AbjA3JKY (ORCPT ); Mon, 30 Jan 2023 04:10:24 -0500 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 763929F; Mon, 30 Jan 2023 01:10:23 -0800 (PST) Received: from [192.168.10.12] (unknown [39.45.165.226]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) (Authenticated sender: usama.anjum) by madras.collabora.co.uk (Postfix) with ESMTPSA id 35DF06602E2A; Mon, 30 Jan 2023 09:10:15 +0000 (GMT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1675069821; bh=/l1ZA909PK+xOECy6RWevd3pYBOOmWKWLYoZHDERZd8=; h=Date:Cc:Subject:To:References:From:In-Reply-To:From; b=VXjvZz+hCCgMh9CNLBkp08d1EtF4OT//jWEFDvgnJuR54ryFfcB82MGaOOymQGIhq k+VqrLhTOWhFgL9CRaE1GjOI4aXCfgyfQV00hwCQZgMu4qPbr5/CWcksAA8KRYgW0D sD3jhX82/6V5IWZInIh23Ux3H5NY3DX8zJKYkfvMx8W4BbOdGg0VecV4A9xy3yGABr K+QEJnPQMT4HN70Ue9QBllXQHdTyBSnzCdzBqh2KmM0/PxCh2Xr7lba5rvwKW2LMTk p8g3hpdTWa4ZGQSVJIa4Ckj3RVgKIo2uuL/Bl9euykx3U94MW0kUUSXAsXUfrtsgKd ntxb0+Jp+Kzgg== Message-ID: Date: Mon, 30 Jan 2023 14:10:11 +0500 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.6.0 Cc: Muhammad Usama Anjum , David Hildenbrand , Andrew Morton , =?UTF-8?B?TWljaGHFgiBNaXJvc8WC?= =?UTF-8?Q?aw?= , Andrei Vagin , Danylo Mocherniuk , Paul Gofman , Cyrill Gorcunov , Alexander Viro , Shuah Khan , Christian Brauner , Yang Shi , Vlastimil Babka , "Liam R . Howlett" , Yun Zhou , Suren Baghdasaryan , Alex Sierra , Matthew Wilcox , Pasha Tatashin , Mike Rapoport , Nadav Amit , Axel Rasmussen , "Gustavo A . R . Silva" , Dan Williams , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, Greg KH , kernel@collabora.com Subject: Re: [PATCH v8 2/4] userfaultfd: split mwriteprotect_range() Content-Language: en-US To: Peter Xu References: <20230124084323.1363825-1-usama.anjum@collabora.com> <20230124084323.1363825-3-usama.anjum@collabora.com> From: Muhammad Usama Anjum In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 1/27/23 10:05 PM, Peter Xu wrote: > On Tue, Jan 24, 2023 at 01:43:21PM +0500, Muhammad Usama Anjum wrote: >> Split mwriteprotect_range() to create a unlocked version. This >> will be used in the next patch to write protect a memory area. >> Add a helper function, wp_range_async() as well. >> >> Signed-off-by: Muhammad Usama Anjum > > IIUC this patch is not needed. You have a stable vma, so I think you can > directly use uffd_wp_range(), while most of the mwriteprotect_range() is > not needed. > > There's one trivial detail of ignoring userfaultfd_ctx->mmap_changing when > it's set to true, but I don't think it applies here either because it was > used to resolve a problem in uffd non-cooperative mode on the predictable > behavior of events, here I don't think it matters a lot either. > Thanks, I'll drop this patch and do direct wiring to uffd_wp_range(). -- BR, Muhammad Usama Anjum