[v2] bcache: Use vmalloc_array() to improve code

[PATCH v2] bcache: Use vmalloc_array() to improve code

Posted by tanze 3 months, 2 weeks ago

Remove array_size() calls and replace vmalloc(),
due to vmalloc_array() being optimized better,
using fewer instructions, and handling overflow more concisely.

Signed-off-by: tanze <tanze@kylinos.cn>
---
Hi, Coly Li.

Thank you for your suggestions. 
I have made revisions according to your requirements. 
Do you have any further suggestions?

---
Changes in v2:
- Fix coding style and formatting issues.
---
 drivers/md/bcache/sysfs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 826b14cae4e5..1ecd2cb3d302 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -1061,8 +1061,8 @@ SHOW(__bch_cache)
 		uint16_t q[31], *p, *cached;
 		ssize_t ret;
 
-		cached = p = vmalloc(array_size(sizeof(uint16_t),
-						ca->sb.nbuckets));
+		cached = p = vmalloc_array(ca->sb.nbuckets, sizeof(uint16_t));
+
 		if (!p)
 			return -ENOMEM;
 
-- 
2.25.1

Re: [PATCH v2] bcache: Use vmalloc_array() to improve code

Posted by Coly Li 3 months, 2 weeks ago

On Thu, Oct 23, 2025 at 10:26:42AM +0800, tanze wrote:
> Remove array_size() calls and replace vmalloc(),
> due to vmalloc_array() being optimized better,
> using fewer instructions, and handling overflow more concisely.
> 
> Signed-off-by: tanze <tanze@kylinos.cn>
> ---
> Hi, Coly Li.
> 
> Thank you for your suggestions. 
> I have made revisions according to your requirements. 
> Do you have any further suggestions?
> 
> ---
> Changes in v2:
> - Fix coding style and formatting issues.
> ---
>  drivers/md/bcache/sysfs.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
> index 826b14cae4e5..1ecd2cb3d302 100644
> --- a/drivers/md/bcache/sysfs.c
> +++ b/drivers/md/bcache/sysfs.c
> @@ -1061,8 +1061,8 @@ SHOW(__bch_cache)
>  		uint16_t q[31], *p, *cached;
>  		ssize_t ret;
>  
> -		cached = p = vmalloc(array_size(sizeof(uint16_t),
> -						ca->sb.nbuckets));
> +		cached = p = vmalloc_array(ca->sb.nbuckets, sizeof(uint16_t));
> +
^^^^-> this empty line is new in v2 patch, and I would suggest to remove it.


>  		if (!p)
>  			return -ENOMEM;

Rested part looks fine.

Thanks.

Coly Li