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=-17.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 9B189C48BE5 for ; Fri, 18 Jun 2021 02:42:35 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 31F9D613C2 for ; Fri, 18 Jun 2021 02:42:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31F9D613C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 904316B0070; Thu, 17 Jun 2021 22:42:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 8B4436B0071; Thu, 17 Jun 2021 22:42:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72DBF6B0072; Thu, 17 Jun 2021 22:42:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0074.hostedemail.com [216.40.44.74]) by kanga.kvack.org (Postfix) with ESMTP id 404A26B0070 for ; Thu, 17 Jun 2021 22:42:34 -0400 (EDT) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id CFC91BBD0 for ; Fri, 18 Jun 2021 02:42:33 +0000 (UTC) X-FDA: 78265296186.21.A1CB911 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf15.hostedemail.com (Postfix) with ESMTP id 483E9A00025F for ; Fri, 18 Jun 2021 02:42:33 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 0EF0960FF1; Fri, 18 Jun 2021 02:42:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1623984152; bh=hafJ5IUDjp1Ik3inNtiETMdZsJZ7nTkQNqoNrUpELBM=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=TNXxY56Yrp5vbVIXvyG3STK2+clis1qM3yMCz43aOElg0WvKh4wAk0OCiTuB1Nvuz Qz3LfMkUxMKqClbXQZ0jkhFTCb1B0Z7VbkgIHeWpg96ma/AaTHnrHX4+WbXWeCCdoC s9PYWPvMCGse1zAfRcgqFBawkyShBvEAz8Kjao0cMr9209hFDB3d3Svsgr8hrHULQ4 ChvbLrTlo3UuNtWRWsLYvoYwNtQH+5i9/pAwiBknpfL1bMPVa4Tn2UWoaa5R/iut3u tQJjo6wrc2kr42PP+QlCr3zVISm+BIBybGvGCu2zr5H2u30U+Gt7v7jvcdESE5qDTM ItvZk4WYoFQ9Q== Subject: Re: [PATCH v2 2/2] mm/zbud: don't export any zbud API To: Miaohe Lin Cc: akpm@linux-foundation.org, sjenning@redhat.com, ddstreet@ieee.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20210608114515.206992-1-linmiaohe@huawei.com> <20210608114515.206992-3-linmiaohe@huawei.com> <813ac556-4a48-1e29-ad87-1ddb74546ef1@huawei.com> From: Nathan Chancellor Message-ID: <621684b8-7aac-97e5-198e-e62061c79301@kernel.org> Date: Thu, 17 Jun 2021 19:42:30 -0700 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <813ac556-4a48-1e29-ad87-1ddb74546ef1@huawei.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: 483E9A00025F Authentication-Results: imf15.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=TNXxY56Y; spf=pass (imf15.hostedemail.com: domain of nathan@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=nathan@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Stat-Signature: fdh7he3kk5yrba75tu3f1eyftbrruid1 X-HE-Tag: 1623984153-583910 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 6/17/2021 7:28 PM, Miaohe Lin wrote: > 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. :) That seems logical to me. It probably makes sense to send that as a fix patch for this one so Andrew can squash it in. Cheers, Nathan > 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 >> . >> >