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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 03855C433ED for ; Wed, 5 May 2021 10:53:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B73C4613BC for ; Wed, 5 May 2021 10:53:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232404AbhEEKyH (ORCPT ); Wed, 5 May 2021 06:54:07 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:18355 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231431AbhEEKyH (ORCPT ); Wed, 5 May 2021 06:54:07 -0400 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4FZtmR0KVWzlbdw; Wed, 5 May 2021 18:51:03 +0800 (CST) Received: from localhost.localdomain (10.175.104.82) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.498.0; Wed, 5 May 2021 18:53:01 +0800 From: Zheng Yongjun To: , , , CC: Zheng Yongjun , Hulk Robot Subject: [PATCH -next v4] bcache: Use DEFINE_MUTEX() for mutex lock Date: Wed, 5 May 2021 19:06:55 +0800 Message-ID: <20210505110655.1461896-1-zhengyongjun3@huawei.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.175.104.82] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-bcache@vger.kernel.org Mutex lock can be initialized automatically with DEFINE_MUTEX() rather than explicitly calling mutex_init(). This patch will reduce the size of bcache.ko about 16 bytes, the reason as follows: Though this patch will increase the size of .data segment about 32 bytes, it will also reduce the size of .init.text and .rodata.str1.1(at x86_64), .rodata_str1.8(at arm64) total about 48 bytes which reduce the size more than .data segment; Here is the statistics: Sections: (arm64 platform) Idx name size -.init.text 00000240 +.init.text 00000228 -.rodata.str1.8 000012cd +.rodata.str1.8 000012b5 -.data 00000c60 +.data 00000c80 Sections: (x86 platform) Idx name size -.init.text 000001d9 +.init.text 000001bf -.rodata.str1.1 00000c80 +.rodata.str1.1 00000c6d -.data 00000cc0 +.data 00000ce0 Reported-by: Hulk Robot Signed-off-by: Zheng Yongjun --- v4: - change commit log, delete bss information at commit description. v3: - change commit log, delete statistic about .bss segment. v2: - add commit log about the reason why bcache.ko size reduced. --- drivers/md/bcache/super.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 03e1fe4de53d..3635f454309e 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -40,7 +40,7 @@ static const char invalid_uuid[] = { }; static struct kobject *bcache_kobj; -struct mutex bch_register_lock; +DEFINE_MUTEX(bch_register_lock); bool bcache_is_reboot; LIST_HEAD(bch_cache_sets); static LIST_HEAD(uncached_devices); @@ -2869,7 +2869,6 @@ static int __init bcache_init(void) check_module_parameters(); - mutex_init(&bch_register_lock); init_waitqueue_head(&unregister_wait); register_reboot_notifier(&reboot); -- 2.25.1