# 答复: \[PATCH -next v4\] bcache: Use DEFINE\_MUTEX() for mutex lock

- From: zhengyongjun \<hidden\>
- Date: 2021-05-06 08:33:21 
- List: linux-bcache
- Page: https://ratatoskr.run/linux-bcache/2021/05/6359654
- Thread: https://ratatoskr.run/linux-bcache/2021/05/6358193/t.md

```text
I've been on a business trip some time ago and didn't do upstream work. Thanks for your patience:)

-----邮件原件-----
发件人: Coly Li [mailto:colyli@suse.de] 
发送时间: 2021年5月6日 11:27
收件人: zhengyongjun [ref]
抄送: pmail_hulkci [ref]; kent.overstreet@gmail.com; linux-bcache@vger.kernel.org; linux-kernel@vger.kernel.org
主题: Re: [PATCH -next v4] bcache: Use DEFINE_MUTEX() for mutex lock

On 5/5/21 7:06 PM, Zheng Yongjun 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) 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 <redacted>
> Signed-off-by: Zheng Yongjun <redacted>

Added in my for-test queue.

Thanks.

Coly Li

[snipped]
```