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[74.12.30.48]) by smtp.gmail.com with ESMTPSA id bj30-20020a05620a191e00b006b59f02224asm8568940qkb.60.2022.07.20.12.15.44 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 20 Jul 2022 12:15:45 -0700 (PDT) Date: Wed, 20 Jul 2022 15:15:44 -0400 From: Peter Xu To: David Hildenbrand Cc: Nadav Amit , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , Mike Rapoport , Axel Rasmussen , Nadav Amit , Andrea Arcangeli , Andrew Cooper , Andy Lutomirski , Dave Hansen , Peter Zijlstra , Thomas Gleixner , Will Deacon , Yu Zhao , Nick Piggin Subject: Re: [RFC PATCH 01/14] userfaultfd: set dirty and young on writeprotect Message-ID: References: <20220718120212.3180-1-namit@vmware.com> <20220718120212.3180-2-namit@vmware.com> <017facf0-7ef8-3faf-138d-3013a20b37db@redhat.com> <2b4393ce-95c9-dd3e-8495-058a139e771e@redhat.com> MIME-Version: 1.0 In-Reply-To: <2b4393ce-95c9-dd3e-8495-058a139e771e@redhat.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=X2HxbNAs; spf=none (imf07.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658344549; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=rgr6tBel5eS7x9CZwqZNQr12OSq9bS7PlstJEoUtG4Q=; b=r1dkbRHrIfEvCrUD4b2ZWl1pay94xm+WOc3OwklDQoQ7QLPI7QU0WU/y7PiWIokZn+/NMv NHPrnp1onw/wJbTtNksB3U5QnF9C93RG3jlWFkPtD4fh0kfxL0RikFPpz4mcjkUOTCYoJh jU+LEEovQqWcrnX2oHESGOLg4xGXwmQ= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658344549; a=rsa-sha256; cv=none; b=fBK0zAmInhq+POL0B9hC8M6NoBFTKNp4/zWnfX2w17ykg2HZwsvSeXSaiuiZCcVnUDzsDZ qQdLkFYz/ZFQ0SKnS6T5++tH7t8j7Xur/7OKd6otrF6KonFbrWBBvfP0mBJTKSB4GUye5W 5gmCiJqvnmzXRNBGbNtNrF8V5/iD0xI= X-Rspam-User: X-Rspamd-Queue-Id: BABBE40061 Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=X2HxbNAs; spf=none (imf07.hostedemail.com: domain of peterx@redhat.com has no SPF policy when checking 170.10.133.124) smtp.mailfrom=peterx@redhat.com; dmarc=pass (policy=none) header.from=redhat.com X-Stat-Signature: btfefpi8k7y5brjt1wzn55j4wapd3ndb X-Rspamd-Server: rspam07 X-HE-Tag: 1658344549-649656 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 Wed, Jul 20, 2022 at 05:10:37PM +0200, David Hildenbrand wrote: > For pagecache pages it may as well be *plain wrong* to bypass the write > fault handler and simply mark pages dirty+map them writable. Could you elaborate? -- Peter Xu