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 384B8C77B7C for ; Mon, 8 May 2023 01:37:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232496AbjEHBh2 (ORCPT ); Sun, 7 May 2023 21:37:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229960AbjEHBh1 (ORCPT ); Sun, 7 May 2023 21:37:27 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE69F46A8 for ; Sun, 7 May 2023 18:37:25 -0700 (PDT) Received: from dggpemm500009.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QF3h13jszzTkD6; Mon, 8 May 2023 09:32:49 +0800 (CST) Received: from [10.174.179.24] (10.174.179.24) by dggpemm500009.china.huawei.com (7.185.36.225) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.23; Mon, 8 May 2023 09:37:23 +0800 Subject: Re: [PATCH -next v9 0/3] Delay the initialization of zswap To: Chris Li References: <20230411093632.822290-1-liushixin2@huawei.com> <9b2b6dac-9a3d-efcb-9706-44f6df1fe2bf@huawei.com> CC: Seth Jennings , Dan Streetman , Vitaly Wool , Andrew Morton , Nathan Chancellor , Christoph Hellwig , , From: Liu Shixin Message-ID: <6ed055cb-e705-3993-6285-3a30bba15c0d@huawei.com> Date: Mon, 8 May 2023 09:37:23 +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: Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.179.24] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpemm500009.china.huawei.com (7.185.36.225) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2023/5/4 22:53, Chris Li wrote: > On Thu, May 04, 2023 at 03:11:05PM +0800, Liu Shixin wrote: >>> If it is the zswap_pool alone, it means that we can have a smaller patch >>> to get most of your 18M back. >> You're right, the most came from zswap_pool. > Thanks for the confirmation. > >>> I also notice you move a lot of __init function back to normal functions. >>> That would mean those functions wouldn't be able to drop after the >>> initialization phase. That is another reason to move less of the initialization >>> function. >> Thanks for your advice. I've thought about it before, but I thought there is less impact >> for the size of kernel, so I didn't do it. > Let's first agree on the hypothetical patch that only delaying zswap_pool would > have the benefit over V9 on: > - smaller patch, less invasive. > - less kernel text area due to more __init function got free after initialization. > > If we can reach that agreement, then we can discuss how we can get there. > > I think there is a possibility that the delay initialization of zswap_pool > can fall into the "zswap_has_pool = false" case, so you don't need to have > the initialization mutex. Simpler. > > I have my selfish reason as well. I have a much larger pending patch against > the zswap code so the smaller patch would mean less conflict for me. > > I am guilty of giving this feedback late. If you come up with a V10, I will be glad > to review it. Or, if you prefer, I can come up with the smaller patch for you > to review as well. What do you say? You can add a pre-patch to modify it before your patch. Thanks. > > Chris > > . >