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=-13.8 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 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 F3A73C433ED for ; Wed, 7 Apr 2021 12:59:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCB946113A for ; Wed, 7 Apr 2021 12:59:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352510AbhDGM71 convert rfc822-to-8bit (ORCPT ); Wed, 7 Apr 2021 08:59:27 -0400 Received: from vostok.pvgoran.name ([71.19.149.48]:48783 "EHLO vostok.pvgoran.name" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231892AbhDGM7Z (ORCPT ); Wed, 7 Apr 2021 08:59:25 -0400 X-Greylist: delayed 302 seconds by postgrey-1.27 at vger.kernel.org; Wed, 07 Apr 2021 08:59:25 EDT Received: from [10.0.10.127] (l37-193-246-51.novotelecom.ru [::ffff:37.193.246.51]) (AUTH: CRAM-MD5 main-collector@pvgoran.name, ) by vostok.pvgoran.name with ESMTPSA id 000000000000D1D4.00000000606DAB74.0000055E; Wed, 07 Apr 2021 12:54:11 +0000 Date: Wed, 7 Apr 2021 19:54:09 +0700 From: Pavel Goran X-Mailer: The Bat! (v3.85.03) Professional Reply-To: Pavel Goran X-Priority: 3 (Normal) Message-ID: <807301067.20210407195409@pvgoran.name> To: Zheng Yongjun CC: colyli@suse.de, kent.overstreet@gmail.com, linux-bcache@vger.kernel.org, linux-kernel@vger.kernel.org, Hulk Robot Subject: Re: [PATCH -next v3] bcache: use DEFINE_MUTEX() for mutex lock In-Reply-To: <20210407125000.858219-1-zhengyongjun3@huawei.com> References: <20210407125000.858219-1-zhengyongjun3@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1251 Content-Transfer-Encoding: 8BIT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Zheng, The third paragraph of the commit description still mentions the .bss segment. Wednesday, April 7, 2021, 7:50:00 PM, you wrote: > 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) and .bss segment 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 > --- > 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); > Pavel Goran