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=-5.2 required=3.0 tests=BAYES_00, 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 C4333C433E6 for ; Wed, 27 Jan 2021 22:16:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9B73661601 for ; Wed, 27 Jan 2021 22:16:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236981AbhA0WQL (ORCPT ); Wed, 27 Jan 2021 17:16:11 -0500 Received: from jabberwock.ucw.cz ([46.255.230.98]:37418 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231153AbhA0WQD (ORCPT ); Wed, 27 Jan 2021 17:16:03 -0500 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 88E5B1C0B8E; Wed, 27 Jan 2021 23:15:05 +0100 (CET) Date: Wed, 27 Jan 2021 23:15:05 +0100 From: Pavel Machek To: Adrian Catangiu Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, gregkh@linuxfoundation.org, graf@amazon.com, arnd@arndb.de, ebiederm@xmission.com, rppt@kernel.org, 0x7f454c46@gmail.com, borntraeger@de.ibm.com, Jason@zx2c4.com, jannh@google.com, w@1wt.eu, colmmacc@amazon.com, luto@kernel.org, tytso@mit.edu, ebiggers@kernel.org, dwmw@amazon.co.uk, bonzini@gnu.org, sblbir@amazon.com, raduweis@amazon.com, corbet@lwn.net, mst@redhat.com, mhocko@kernel.org, rafael@kernel.org, mpe@ellerman.id.au, areber@redhat.com, ovzxemul@gmail.com, avagin@gmail.com, ptikhomirov@virtuozzo.com, gil@azul.com, asmehra@redhat.com, dgunigun@redhat.com, vijaysun@ca.ibm.com, oridgar@gmail.com, ghammer@redhat.com Subject: Re: [PATCH v4 1/2] drivers/misc: sysgenid: add system generation id driver Message-ID: <20210127221505.GB24799@amd> References: <1610453760-13812-1-git-send-email-acatan@amazon.com> <1610453760-13812-2-git-send-email-acatan@amazon.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qlTNgmc+xy1dBmNv" Content-Disposition: inline In-Reply-To: <1610453760-13812-2-git-send-email-acatan@amazon.com> User-Agent: Mutt/1.5.23 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --qlTNgmc+xy1dBmNv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > - Solution >=20 > The System Generation ID is a simple concept meant to alleviate the > issue by providing a monotonically increasing u32 counter that changes > each time the VM or container is restored from a snapshot. I'd make it u64. But as people explained, this has race problems that may be impossible to solve? Best regards, Pavel =09 --=20 http://www.livejournal.com/~pavelmachek --qlTNgmc+xy1dBmNv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmAR5ekACgkQMOfwapXb+vIeRACdFFlEw9Qzjgj/nAuNJzxFeb2z 28wAoKXL22jBt2ohyVp9BgmFr64wldNZ =T3KQ -----END PGP SIGNATURE----- --qlTNgmc+xy1dBmNv-- 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=-5.2 required=3.0 tests=BAYES_00, 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 CCFB8C433DB for ; Wed, 27 Jan 2021 22:16:44 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5FBCE64DCC for ; Wed, 27 Jan 2021 22:16:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5FBCE64DCC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ucw.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40050 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1l4t7D-0007N9-E8 for qemu-devel@archiver.kernel.org; Wed, 27 Jan 2021 17:16:43 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:52474) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l4t5z-0006kP-37 for qemu-devel@nongnu.org; Wed, 27 Jan 2021 17:15:29 -0500 Received: from jabberwock.ucw.cz ([46.255.230.98]:58944) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1l4t5l-0006pd-1j for qemu-devel@nongnu.org; Wed, 27 Jan 2021 17:15:22 -0500 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 88E5B1C0B8E; Wed, 27 Jan 2021 23:15:05 +0100 (CET) Date: Wed, 27 Jan 2021 23:15:05 +0100 From: Pavel Machek To: Adrian Catangiu Subject: Re: [PATCH v4 1/2] drivers/misc: sysgenid: add system generation id driver Message-ID: <20210127221505.GB24799@amd> References: <1610453760-13812-1-git-send-email-acatan@amazon.com> <1610453760-13812-2-git-send-email-acatan@amazon.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="qlTNgmc+xy1dBmNv" Content-Disposition: inline In-Reply-To: <1610453760-13812-2-git-send-email-acatan@amazon.com> User-Agent: Mutt/1.5.23 (2014-03-12) Received-SPF: none client-ip=46.255.230.98; envelope-from=pavel@ucw.cz; helo=jabberwock.ucw.cz X-Spam_score_int: -18 X-Spam_score: -1.9 X-Spam_bar: - X-Spam_report: (-1.9 / 5.0 requ) BAYES_00=-1.9, SPF_HELO_NONE=0.001, SPF_NONE=0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jason@zx2c4.com, dgunigun@redhat.com, kvm@vger.kernel.org, linux-doc@vger.kernel.org, ghammer@redhat.com, vijaysun@ca.ibm.com, 0x7f454c46@gmail.com, qemu-devel@nongnu.org, mhocko@kernel.org, oridgar@gmail.com, avagin@gmail.com, ptikhomirov@virtuozzo.com, linux-s390@vger.kernel.org, corbet@lwn.net, mpe@ellerman.id.au, mst@redhat.com, ebiggers@kernel.org, borntraeger@de.ibm.com, sblbir@amazon.com, bonzini@gnu.org, arnd@arndb.de, jannh@google.com, raduweis@amazon.com, asmehra@redhat.com, graf@amazon.com, rppt@kernel.org, luto@kernel.org, gil@azul.com, colmmacc@amazon.com, tytso@mit.edu, gregkh@linuxfoundation.org, areber@redhat.com, linux-kernel@vger.kernel.org, ebiederm@xmission.com, ovzxemul@gmail.com, rafael@kernel.org, w@1wt.eu, dwmw@amazon.co.uk Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" --qlTNgmc+xy1dBmNv Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi! > - Solution >=20 > The System Generation ID is a simple concept meant to alleviate the > issue by providing a monotonically increasing u32 counter that changes > each time the VM or container is restored from a snapshot. I'd make it u64. But as people explained, this has race problems that may be impossible to solve? Best regards, Pavel =09 --=20 http://www.livejournal.com/~pavelmachek --qlTNgmc+xy1dBmNv Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEYEARECAAYFAmAR5ekACgkQMOfwapXb+vIeRACdFFlEw9Qzjgj/nAuNJzxFeb2z 28wAoKXL22jBt2ohyVp9BgmFr64wldNZ =T3KQ -----END PGP SIGNATURE----- --qlTNgmc+xy1dBmNv--