Re: [PATCH 05/24] RDMA: use dma_resv_wait() instead of extracting the fence

[Daniel Vetter <daniel@ffwll.ch>]

On Tue, Dec 07, 2021 at 01:33:52PM +0100, Christian König wrote:
> Use dma_resv_wait() instead of extracting the exclusive fence and
> waiting on it manually.
> 
> Signed-off-by: Christian König <christian.koenig@amd.com>

No rdma lists nor maintainers on cc, so no chances to get the ack you need
to merge this through drm-misc-next.


> ---
>  drivers/infiniband/core/umem_dmabuf.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/infiniband/core/umem_dmabuf.c b/drivers/infiniband/core/umem_dmabuf.c
> index f0760741f281..d32cd7538835 100644
> --- a/drivers/infiniband/core/umem_dmabuf.c
> +++ b/drivers/infiniband/core/umem_dmabuf.c
> @@ -16,7 +16,6 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
>  {
>  	struct sg_table *sgt;
>  	struct scatterlist *sg;
> -	struct dma_fence *fence;
>  	unsigned long start, end, cur = 0;
>  	unsigned int nmap = 0;
>  	int i;
> @@ -68,11 +67,8 @@ int ib_umem_dmabuf_map_pages(struct ib_umem_dmabuf *umem_dmabuf)
>  	 * may be not up-to-date. Wait for the exporter to finish
>  	 * the migration.
>  	 */
> -	fence = dma_resv_excl_fence(umem_dmabuf->attach->dmabuf->resv);
> -	if (fence)
> -		return dma_fence_wait(fence, false);
> -
> -	return 0;
> +	return dma_resv_wait_timeout(umem_dmabuf->attach->dmabuf->resv, false,
> +				     false, MAX_SCHEDULE_TIMEOUT);

I think a wrapper for dma_resv_wait() without timeout would be neat, which
we lack. Either way:

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

>  }
>  EXPORT_SYMBOL(ib_umem_dmabuf_map_pages);
>  
> -- 
> 2.25.1
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch