2021-04-29 10:22:47

by Jiapeng Chong

Subject: [PATCH] hv_balloon: Remove redundant assignment to region_start

Variable region_start is set to pg_start but this value is never
read as it is overwritten later on, hence it is a redundant
assignment and can be removed.

Cleans up the following clang-analyzer warning:

drivers/hv/hv_balloon.c:1013:3: warning: Value stored to 'region_start'
is never read [clang-analyzer-deadcode.DeadStores].

Reported-by: Abaci Robot <[email protected]>
Signed-off-by: Jiapeng Chong <[email protected]>
---
drivers/hv/hv_balloon.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
index 58af84e..7f11ea0 100644
--- a/drivers/hv/hv_balloon.c
+++ b/drivers/hv/hv_balloon.c
@@ -1010,7 +1010,6 @@ static void hot_add_req(struct work_struct *dummy)
* that need to be hot-added while ensuring the alignment
* and size requirements of Linux as it relates to hot-add.
*/
- region_start = pg_start;
region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
if (pfn_cnt % HA_CHUNK)
region_size += HA_CHUNK;
--
1.8.3.1

2021-05-04 12:56:24

by Wei Liu

Subject: Re: [PATCH] hv_balloon: Remove redundant assignment to region_start

On Thu, Apr 29, 2021 at 06:21:21PM +0800, Jiapeng Chong wrote:
> Variable region_start is set to pg_start but this value is never
> read as it is overwritten later on, hence it is a redundant
> assignment and can be removed.

Indeed. It is overwritten a few lines below.

>
> Cleans up the following clang-analyzer warning:
>
> drivers/hv/hv_balloon.c:1013:3: warning: Value stored to 'region_start'
> is never read [clang-analyzer-deadcode.DeadStores].
>
> Reported-by: Abaci Robot <[email protected]>
> Signed-off-by: Jiapeng Chong <[email protected]>

Applied to hyperv-next. Thanks.

Wei.

> ---
> drivers/hv/hv_balloon.c | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c
> index 58af84e..7f11ea0 100644
> --- a/drivers/hv/hv_balloon.c
> +++ b/drivers/hv/hv_balloon.c
> @@ -1010,7 +1010,6 @@ static void hot_add_req(struct work_struct *dummy)
> * that need to be hot-added while ensuring the alignment
> * and size requirements of Linux as it relates to hot-add.
> */
> - region_start = pg_start;
> region_size = (pfn_cnt / HA_CHUNK) * HA_CHUNK;
> if (pfn_cnt % HA_CHUNK)
> region_size += HA_CHUNK;
> --
> 1.8.3.1
>