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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,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 5B429C33CA1 for ; Wed, 5 Feb 2020 09:58:29 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 085592051A for ; Wed, 5 Feb 2020 09:58:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aTSyvFrV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 085592051A Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 92AE86B00A2; Wed, 5 Feb 2020 04:58:28 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 8DBF46B00A3; Wed, 5 Feb 2020 04:58:28 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 7F23A6B00A4; Wed, 5 Feb 2020 04:58:28 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0189.hostedemail.com [216.40.44.189]) by kanga.kvack.org (Postfix) with ESMTP id 67D846B00A2 for ; Wed, 5 Feb 2020 04:58:28 -0500 (EST) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0CF3D2C04 for ; Wed, 5 Feb 2020 09:58:28 +0000 (UTC) X-FDA: 76455623496.13.hose14_66e89b54cde22 X-HE-Tag: hose14_66e89b54cde22 X-Filterd-Recvd-Size: 7739 Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Wed, 5 Feb 2020 09:58:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580896706; 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: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=XlNjNRrB+ElVg4pdnyWYuEOXmgn6hwLghbf57sW01yA=; b=aTSyvFrVYTj4k39qvtOyIofv/UXa7BPaoteLAE6BGdL3PzMFLFJF9T0oesTEYgcKFjsJ3h LpqqyEY21ARjIpSnYQ9jCanDR8au90M5uvgkAzlAiQjIz0kKLp1Kz9EUndUmUb3YHKpSUd F28QoFINg7s4R0GqaLIWaw8ATNRI5YI= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-351-eFBsGo6vPtaUKt2nDOgIpw-1; Wed, 05 Feb 2020 04:58:22 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E2151DB6E; Wed, 5 Feb 2020 09:58:20 +0000 (UTC) Received: from [10.36.116.217] (ovpn-116-217.ams2.redhat.com [10.36.116.217]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8F55D4731B; Wed, 5 Feb 2020 09:58:15 +0000 (UTC) Subject: Re: Balloon pressuring page cache To: "Wang, Wei W" , "Michael S. Tsirkin" Cc: Nadav Amit , Alexander Duyck , Tyler Sanderson , "virtualization@lists.linux-foundation.org" , David Rientjes , "linux-mm@kvack.org" , Michal Hocko References: <91270a68-ff48-88b0-219c-69801f0c252f@redhat.com> <539B606A-A0CA-4AA4-B99A-759C874A1EF8@vmware.com> <20200204033657-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F73E41F0F0@shsmsx102.ccr.corp.intel.com> <1eff30a0-a38a-cd45-2fc1-80cfd0bf5f04@redhat.com> <286AC319A985734F985F78AFA26841F73E41F306@shsmsx102.ccr.corp.intel.com> <2b388a78-79cd-f99a-6f87-6446dcb4b819@redhat.com> <286AC319A985734F985F78AFA26841F73E41F367@shsmsx102.ccr.corp.intel.com> <605bef3e-373f-f39a-4849-930326564b5b@redhat.com> <286AC319A985734F985F78AFA26841F73E41F3DE@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73E41F490@shsmsx102.ccr.corp.intel.com> <5b184893-014c-35a1-928b-37b8f4647116@redhat.com> <286AC319A985734F985F78AFA26841F73E41F562@shsmsx102.ccr.corp.intel.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= mQINBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABtCREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT6JAlgEEwEIAEICGwMFCQlmAYAGCwkIBwMCBhUI AgkKCwQWAgMBAh4BAheAFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl3pImkCGQEACgkQTd4Q 9wD/g1o+VA//SFvIHUAvul05u6wKv/pIR6aICPdpF9EIgEU448g+7FfDgQwcEny1pbEzAmiw zAXIQ9H0NZh96lcq+yDLtONnXk/bEYWHHUA014A1wqcYNRY8RvY1+eVHb0uu0KYQoXkzvu+s Dncuguk470XPnscL27hs8PgOP6QjG4jt75K2LfZ0eAqTOUCZTJxA8A7E9+XTYuU0hs7QVrWJ jQdFxQbRMrYz7uP8KmTK9/Cnvqehgl4EzyRaZppshruKMeyheBgvgJd5On1wWq4ZUV5PFM4x II3QbD3EJfWbaJMR55jI9dMFa+vK7MFz3rhWOkEx/QR959lfdRSTXdxs8V3zDvChcmRVGN8U Vo93d1YNtWnA9w6oCW1dnDZ4kgQZZSBIjp6iHcA08apzh7DPi08jL7M9UQByeYGr8KuR4i6e RZI6xhlZerUScVzn35ONwOC91VdYiQgjemiVLq1WDDZ3B7DIzUZ4RQTOaIWdtXBWb8zWakt/ ztGhsx0e39Gvt3391O1PgcA7ilhvqrBPemJrlb9xSPPRbaNAW39P8ws/UJnzSJqnHMVxbRZC Am4add/SM+OCP0w3xYss1jy9T+XdZa0lhUvJfLy7tNcjVG/sxkBXOaSC24MFPuwnoC9WvCVQ ZBxouph3kqc4Dt5X1EeXVLeba+466P1fe1rC8MbcwDkoUo65Ag0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAGJAiUEGAECAA8FAlXLn5ECGwwFCQlmAYAACgkQTd4Q 9wD/g1qA6w/+M+ggFv+JdVsz5+ZIc6MSyGUozASX+bmIuPeIecc9UsFRatc91LuJCKMkD9Uv GOcWSeFpLrSGRQ1Z7EMzFVU//qVs6uzhsNk0RYMyS0B6oloW3FpyQ+zOVylFWQCzoyyf227y GW8HnXunJSC+4PtlL2AY4yZjAVAPLK2l6mhgClVXTQ/S7cBoTQKP+jvVJOoYkpnFxWE9pn4t H5QIFk7Ip8TKr5k3fXVWk4lnUi9MTF/5L/mWqdyIO1s7cjharQCstfWCzWrVeVctpVoDfJWp 4LwTuQ5yEM2KcPeElLg5fR7WB2zH97oI6/Ko2DlovmfQqXh9xWozQt0iGy5tWzh6I0JrlcxJ ileZWLccC4XKD1037Hy2FLAjzfoWgwBLA6ULu0exOOdIa58H4PsXtkFPrUF980EEibUp0zFz GotRVekFAceUaRvAj7dh76cToeZkfsjAvBVb4COXuhgX6N4pofgNkW2AtgYu1nUsPAo+NftU CxrhjHtLn4QEBpkbErnXQyMjHpIatlYGutVMS91XTQXYydCh5crMPs7hYVsvnmGHIaB9ZMfB njnuI31KBiLUks+paRkHQlFcgS2N3gkRBzH7xSZ+t7Re3jvXdXEzKBbQ+dC3lpJB0wPnyMcX FOTT3aZT7IgePkt5iC/BKBk3hqKteTnJFeVIT7EC+a6YUFg= Organization: Red Hat GmbH Message-ID: Date: Wed, 5 Feb 2020 10:58:14 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.1 MIME-Version: 1.0 In-Reply-To: <286AC319A985734F985F78AFA26841F73E41F562@shsmsx102.ccr.corp.intel.com> Content-Language: en-US X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-MC-Unique: eFBsGo6vPtaUKt2nDOgIpw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit 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 05.02.20 10:49, Wang, Wei W wrote: > On Wednesday, February 5, 2020 5:37 PM, David Hildenbrand wrote: >>> >>> Not sure how TCG tracks the dirty bits. But In whatever >>> implementation, the hypervisor should have >> >> There is only a single bitmap for that purpose. (well, the one where KVM >> syncs to) >> >>> already dealt with the race between he current round and the previous >> round dirty recording. >>> (the race isn't brought by this feature essentially) >> >> It is guaranteed to work reliably without this feature as you only clear what >> *has been migrated*, > > Not "clear what has been migrated" (that skips nothing..) > Anyway, it's a hint used for optimization. Yes, an optimization that might easily lead to data corruption when the two bitmaps are either not in place or don't play along in that specific way (and I suspect this is the case under TCG). -- Thanks, David / dhildenb From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Hildenbrand Subject: Re: Balloon pressuring page cache Date: Wed, 5 Feb 2020 10:58:14 +0100 Message-ID: References: <91270a68-ff48-88b0-219c-69801f0c252f@redhat.com> <539B606A-A0CA-4AA4-B99A-759C874A1EF8@vmware.com> <20200204033657-mutt-send-email-mst@kernel.org> <286AC319A985734F985F78AFA26841F73E41F0F0@shsmsx102.ccr.corp.intel.com> <1eff30a0-a38a-cd45-2fc1-80cfd0bf5f04@redhat.com> <286AC319A985734F985F78AFA26841F73E41F306@shsmsx102.ccr.corp.intel.com> <2b388a78-79cd-f99a-6f87-6446dcb4b819@redhat.com> <286AC319A985734F985F78AFA26841F73E41F367@shsmsx102.ccr.corp.intel.com> <605bef3e-373f-f39a-4849-930326564b5b@redhat.com> <286AC319A985734F985F78AFA26841F73E41F3DE@shsmsx102.ccr.corp.intel.com> <286AC319A985734F985F78AFA26841F73E41F490@shsmsx102.ccr.corp.intel.com> <5b184893-014c-35a1-928b-37b8f4647116@redhat.com> <286AC319A985734F985F78AFA26841F73E41F562@shsmsx102.ccr.corp.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <286AC319A985734F985F78AFA26841F73E41F562@shsmsx102.ccr.corp.intel.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" To: "Wang, Wei W" , "Michael S. Tsirkin" Cc: "virtualization@lists.linux-foundation.org" , Tyler Sanderson , "linux-mm@kvack.org" , Nadav Amit , David Rientjes , Alexander Duyck , Michal Hocko List-Id: virtualization@lists.linuxfoundation.org On 05.02.20 10:49, Wang, Wei W wrote: > On Wednesday, February 5, 2020 5:37 PM, David Hildenbrand wrote: >>> >>> Not sure how TCG tracks the dirty bits. But In whatever >>> implementation, the hypervisor should have >> >> There is only a single bitmap for that purpose. (well, the one where KVM >> syncs to) >> >>> already dealt with the race between he current round and the previous >> round dirty recording. >>> (the race isn't brought by this feature essentially) >> >> It is guaranteed to work reliably without this feature as you only clear what >> *has been migrated*, > > Not "clear what has been migrated" (that skips nothing..) > Anyway, it's a hint used for optimization. Yes, an optimization that might easily lead to data corruption when the two bitmaps are either not in place or don't play along in that specific way (and I suspect this is the case under TCG). -- Thanks, David / dhildenb