[PATCH] RDMA/rxe: remove redundant assignment to variable page_offset

[PATCH] RDMA/rxe: remove redundant assignment to variable page_offset

[Colin Ian King]

The variable page_offset is being assigned a value at the start of
a loop and being redundantly zero'd at the end of the loop, there
is no code that reads the zero'd value. The assignment is redundant
and can be removed.

Signed-off-by: Colin Ian King <coking@nvidia.com>
---
 drivers/infiniband/sw/rxe/rxe_mr.c  | 1 -
 drivers/infiniband/sw/rxe/rxe_odp.c | 1 -
 2 files changed, 2 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
index bcb97b3ea58a..b1df05238848 100644
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -452,7 +452,6 @@ static int rxe_mr_flush_pmem_iova(struct rxe_mr *mr, u64 iova, unsigned int leng
 
 		length -= bytes;
 		iova += bytes;
-		page_offset = 0;
 	}
 
 	return 0;
diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c
index f58e3ec6252f..ae71812bea82 100644
--- a/drivers/infiniband/sw/rxe/rxe_odp.c
+++ b/drivers/infiniband/sw/rxe/rxe_odp.c
@@ -358,7 +358,6 @@ int rxe_odp_flush_pmem_iova(struct rxe_mr *mr, u64 iova,
 
 		length -= bytes;
 		iova += bytes;
-		page_offset = 0;
 	}
 
 	mutex_unlock(&umem_odp->umem_mutex);
-- 
2.51.0

Re: [PATCH] RDMA/rxe: remove redundant assignment to variable page_offset

[Zhu Yanjun]

在 2025/10/14 5:03, Colin Ian King 写道:
> The variable page_offset is being assigned a value at the start of
> a loop and being redundantly zero'd at the end of the loop, there
> is no code that reads the zero'd value. The assignment is redundant
> and can be removed.
> 
> Signed-off-by: Colin Ian King <coking@nvidia.com>
> ---
>   drivers/infiniband/sw/rxe/rxe_mr.c  | 1 -
>   drivers/infiniband/sw/rxe/rxe_odp.c | 1 -
>   2 files changed, 2 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_mr.c b/drivers/infiniband/sw/rxe/rxe_mr.c
> index bcb97b3ea58a..b1df05238848 100644
> --- a/drivers/infiniband/sw/rxe/rxe_mr.c
> +++ b/drivers/infiniband/sw/rxe/rxe_mr.c
> @@ -452,7 +452,6 @@ static int rxe_mr_flush_pmem_iova(struct rxe_mr *mr, u64 iova, unsigned int leng
>   
>   		length -= bytes;
>   		iova += bytes;
> -		page_offset = 0;
>   	}
static int rxe_mr_flush_pmem_iova(struct rxe_mr *mr, u64 iova, unsigned 
int length)
{
	unsigned int page_offset;
	...
	while (length > 0) {
		index = rxe_mr_iova_to_index(mr, iova);
		page = xa_load(&mr->page_list, index);
		page_offset = rxe_mr_iova_to_page_offset(mr, iova);
	...
		page_offset = 0;
	}

	return 0;
}>
>   	return 0;
> diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c
> index f58e3ec6252f..ae71812bea82 100644
> --- a/drivers/infiniband/sw/rxe/rxe_odp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_odp.c
> @@ -358,7 +358,6 @@ int rxe_odp_flush_pmem_iova(struct rxe_mr *mr, u64 iova,
>   
>   		length -= bytes;
>   		iova += bytes;
> -		page_offset = 0;
>   	}
int rxe_odp_flush_pmem_iova(struct rxe_mr *mr, u64 iova,
			    unsigned int length)
{
	unsigned int page_offset;
...
	while (length > 0) {
		index = rxe_odp_iova_to_index(umem_odp, iova);
		page_offset = rxe_odp_iova_to_page_offset(umem_odp, iova);
...
		page_offset = 0;
	}

	mutex_unlock(&umem_odp->umem_mutex);

	return 0;
}
 From the above, in the functions rxe_mr_flush_pmem_iova and 
rxe_odp_flush_pmem_iova, within the while loop, the variable page_offset 
is assigned a value. At the end of the loop, page_offset is set to 0. 
However, this assignment at the end of the loop is actually unnecessary.

Thanks,
Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Zhu Yanjun

>   
>   	mutex_unlock(&umem_odp->umem_mutex);

Re: [PATCH] RDMA/rxe: remove redundant assignment to variable page_offset

[Leon Romanovsky]

On Tue, 14 Oct 2025 13:03:43 +0100, Colin Ian King wrote:
> The variable page_offset is being assigned a value at the start of
> a loop and being redundantly zero'd at the end of the loop, there
> is no code that reads the zero'd value. The assignment is redundant
> and can be removed.
> 
> 

Applied, thanks!

[1/1] RDMA/rxe: remove redundant assignment to variable page_offset
      https://git.kernel.org/rdma/rdma/c/1511efaca032ed

Best regards,
-- 
Leon Romanovsky <leon@kernel.org>