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=-15.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 316D0C2B9F4 for ; Fri, 18 Jun 2021 02:29:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A0FEE613BA for ; Fri, 18 Jun 2021 02:29:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A0FEE613BA Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9FDCA6B0070; Thu, 17 Jun 2021 22:29:03 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9ADA36B0071; Thu, 17 Jun 2021 22:29:03 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 84E836B0072; Thu, 17 Jun 2021 22:29:03 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0039.hostedemail.com [216.40.44.39]) by kanga.kvack.org (Postfix) with ESMTP id 53ACB6B0070 for ; Thu, 17 Jun 2021 22:29:03 -0400 (EDT) Received: from smtpin06.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id CB9028249980 for ; Fri, 18 Jun 2021 02:29:02 +0000 (UTC) X-FDA: 78265262124.06.ABDA0F4 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by imf02.hostedemail.com (Postfix) with ESMTP id 7A2614202A08 for ; Fri, 18 Jun 2021 02:29:01 +0000 (UTC) Received: from dggeme703-chm.china.huawei.com (unknown [172.30.72.56]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4G5jQx5JYJzXgkK; Fri, 18 Jun 2021 10:23:53 +0800 (CST) Received: from [10.174.176.146] (10.174.176.146) by dggeme703-chm.china.huawei.com (10.1.199.99) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Fri, 18 Jun 2021 10:28:56 +0800 Subject: Re: [PATCH v2 2/2] mm/zbud: don't export any zbud API To: Nathan Chancellor CC: , , , , References: <20210608114515.206992-1-linmiaohe@huawei.com> <20210608114515.206992-3-linmiaohe@huawei.com> From: Miaohe Lin Message-ID: <813ac556-4a48-1e29-ad87-1ddb74546ef1@huawei.com> Date: Fri, 18 Jun 2021 10:28:56 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.146] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggeme703-chm.china.huawei.com (10.1.199.99) X-CFilter-Loop: Reflected Authentication-Results: imf02.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=huawei.com; spf=pass (imf02.hostedemail.com: domain of linmiaohe@huawei.com designates 45.249.212.187 as permitted sender) smtp.mailfrom=linmiaohe@huawei.com X-Rspamd-Server: rspam02 X-Stat-Signature: 76iaoof6fzmktw4or5zedp4bcgq3qosb X-Rspamd-Queue-Id: 7A2614202A08 X-HE-Tag: 1623983341-328136 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: Hi: On 2021/6/18 8:44, Nathan Chancellor wrote: > On Tue, Jun 08, 2021 at 07:45:15PM +0800, Miaohe Lin wrote: >> The zbud doesn't need to export any API and it is meant to be used via >> zpool API since the commit 12d79d64bfd3 ("mm/zpool: update zswap to use >> zpool"). So we can remove the unneeded zbud.h and move down zpool API >> to avoid any forward declaration. >> >> Signed-off-by: Miaohe Lin > Thank you for help figure these warnings out. It seems zbud module won't do anything when CONFIG_ZPOOL is disabled. I think we should make zbud depends on ZPOOL and eliminate the CONFIG_ZPOOL macro in zbud.c like what z3fold does. Does this make sense for you? Thanks again. :) diff --git a/mm/Kconfig b/mm/Kconfig index 8f748010f7ea..5dc28e9205e0 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -674,6 +674,7 @@ config ZPOOL config ZBUD tristate "Low (Up to 2x) density storage for compressed pages" + depends on ZPOOL help A special purpose allocator for storing compressed pages. It is designed to store up to two compressed pages per physical diff --git a/mm/zbud.c b/mm/zbud.c index 3f61304405cb..6348932430b8 100644 --- a/mm/zbud.c +++ b/mm/zbud.c @@ -111,10 +111,8 @@ struct zbud_pool { struct list_head lru; u64 pages_nr; const struct zbud_ops *ops; -#ifdef CONFIG_ZPOOL struct zpool *zpool; const struct zpool_ops *zpool_ops; -#endif }; /* @@ -526,8 +524,6 @@ static u64 zbud_get_pool_size(struct zbud_pool *pool) * zpool ****************/ -#ifdef CONFIG_ZPOOL - static int zbud_zpool_evict(struct zbud_pool *pool, unsigned long handle) { if (pool->zpool && pool->zpool_ops && pool->zpool_ops->evict) @@ -618,7 +614,6 @@ static struct zpool_driver zbud_zpool_driver = { }; MODULE_ALIAS("zpool-zbud"); -#endif /* CONFIG_ZPOOL */ static int __init init_zbud(void) { @@ -626,19 +621,14 @@ static int __init init_zbud(void) BUILD_BUG_ON(sizeof(struct zbud_header) > ZHDR_SIZE_ALIGNED); pr_info("loaded\n"); -#ifdef CONFIG_ZPOOL zpool_register_driver(&zbud_zpool_driver); -#endif return 0; } static void __exit exit_zbud(void) { -#ifdef CONFIG_ZPOOL zpool_unregister_driver(&zbud_zpool_driver); -#endif - pr_info("unloaded\n"); } > This patch causes several new warnings when CONFIG_ZPOOL is disabled: > > mm/zbud.c:222:26: warning: unused function 'zbud_create_pool' [-Wunused-function] > mm/zbud.c:246:13: warning: unused function 'zbud_destroy_pool' [-Wunused-function] > mm/zbud.c:270:12: warning: unused function 'zbud_alloc' [-Wunused-function] > mm/zbud.c:345:13: warning: unused function 'zbud_free' [-Wunused-function] > mm/zbud.c:417:12: warning: unused function 'zbud_reclaim_page' [-Wunused-function] > mm/zbud.c:499:14: warning: unused function 'zbud_map' [-Wunused-function] > mm/zbud.c:509:13: warning: unused function 'zbud_unmap' [-Wunused-function] > mm/zbud.c:520:12: warning: unused function 'zbud_get_pool_size' [-Wunused-function] > > It seems to me like all of these functions should be sunk into their > callers and eliminated entirely as part of this refactoring. I took a > whack at it but got lost with the kernel docs so someone who is familiar > with this should probably do it. > > Cheers, > Nathan > . >