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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7437DC54EE9 for ; Wed, 21 Sep 2022 01:42:47 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id CE619940007; Tue, 20 Sep 2022 21:42:46 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C94EF6B0073; Tue, 20 Sep 2022 21:42:46 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B359D940007; Tue, 20 Sep 2022 21:42:46 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A163F6B0072 for ; Tue, 20 Sep 2022 21:42:46 -0400 (EDT) Received: from smtpin05.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 798FD140458 for ; Wed, 21 Sep 2022 01:42:46 +0000 (UTC) X-FDA: 79934393532.05.40F54CD Received: from szxga03-in.huawei.com (szxga03-in.huawei.com [45.249.212.189]) by imf07.hostedemail.com (Postfix) with ESMTP id CBE7340015 for ; Wed, 21 Sep 2022 01:42:45 +0000 (UTC) Received: from dggpemm500022.china.huawei.com (unknown [172.30.72.54]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4MXLhd0TlKzHpcL; Wed, 21 Sep 2022 09:40:33 +0800 (CST) Received: from dggpemm100009.china.huawei.com (7.185.36.113) by dggpemm500022.china.huawei.com (7.185.36.162) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 21 Sep 2022 09:42:42 +0800 Received: from [10.174.179.24] (10.174.179.24) by dggpemm100009.china.huawei.com (7.185.36.113) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.31; Wed, 21 Sep 2022 09:42:41 +0800 Subject: Re: [PATCH v5 2/5] Revert "frontswap: simplify frontswap_register_ops" To: Christoph Hellwig References: <20220915035003.3347466-1-liushixin2@huawei.com> <20220915035003.3347466-3-liushixin2@huawei.com> <20220920121305.GA4237@lst.de> CC: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , , , Kefeng Wang From: Liu Shixin Message-ID: <2b469a5c-7960-ca6a-9360-c7d3aa26e8ae@huawei.com> Date: Wed, 21 Sep 2022 09:42:41 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20220920121305.GA4237@lst.de> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.24] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To dggpemm100009.china.huawei.com (7.185.36.113) X-CFilter-Loop: Reflected ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf07.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=liushixin2@huawei.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1663724566; a=rsa-sha256; cv=none; b=lAeoUIcugdUTn18fHAcocR7BkJBTrWt/O3iQ3DlPfLRg2XO+t9uqrWof1Ipvo5m5bB0tK5 5ueRovQQ1RBn6qVTjbJIbIBJ1yoz/cOP3V2hPy6hgsBuJdiXFhb/B5bZ+N5itgL/mJ3RWq SNIah6ppVoS7Pocj8eaMRxiCfgnI24Y= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1663724566; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/qR5XyjbpIIGqXkPd32zMvOtAQb1qAXqJ7Oejkz2G2Q=; b=OXD8ChNM4kVP4fP0T9Aw1OR1uWr32qzgUqPA6KTuLTnXn+xbYRZtfUMksUHBnZUi3P8Vuk rvjFUQJ9Qzo7Yy3FBvjT4vaS6guaujr77soW4ueJVTRgkSpE6KUXuh1nWjYxAmVAdmtJPK i8Cr4v+rKcntA2pFDbbWKlylNK7LUzo= X-Stat-Signature: j7s9u5agboezuc7h8qqe1j8izh93e1ed X-Rspamd-Queue-Id: CBE7340015 Authentication-Results: imf07.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf07.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.189 as permitted sender) smtp.mailfrom=liushixin2@huawei.com X-Rspam-User: X-Rspamd-Server: rspam09 X-HE-Tag: 1663724565-476991 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 2022/9/20 20:13, Christoph Hellwig wrote: > On Thu, Sep 15, 2022 at 11:50:00AM +0800, Liu Shixin wrote: >> This reverts commit f328c1d16e4c764992895ac9c9425cea861b2ca0. >> >> Since we are supported to delay zswap initializaton, we need to invoke >> ops->init for the swap device which is already online when register >> backend. > Why do we "have" to do it. Retroactively supporting functionality on > previously enabled swap devices seems rather odd, and the amount of > cruft added for it here absolutely does not seem to be worth it. Hi Christoph, This revert makes code complicated, but I think it's necessary. When enable zswap, I expect it to work for all swap devices as much as possible. In this way, user can enable zswap and swap device in any order. Since we can enable zswap on previously swap devices, why not support it to get such benifit? Thanks, > . >