Re: [PATCH 1/1] RDMA/rxe: Use a dedicated and robust workqueue for RXE tasks

[Leon Romanovsky <leon@kernel.org>]

On Wed, Mar 18, 2026 at 03:57:39AM +0100, Zhu Yanjun wrote:
> Currently, the RXE driver uses the system-wide 'system_unbound_wq' for
> auxiliary tasks like ODP prefetching. This can lead to interference
> from other system services and lacks guaranteed forward progress
> under memory pressure.
> 
> Currently make all the tasks queue into the driver-specific 'rxe_wq'.
> 
> Suggested-by: Leon Romanovsky <leon@kernel.org>
> Signed-off-by: Zhu Yanjun <yanjun.zhu@linux.dev>
> ---
>  drivers/infiniband/sw/rxe/rxe_odp.c  |  2 +-
>  drivers/infiniband/sw/rxe/rxe_task.c | 10 +++++++++-
>  drivers/infiniband/sw/rxe/rxe_task.h |  1 +
>  3 files changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/sw/rxe/rxe_odp.c b/drivers/infiniband/sw/rxe/rxe_odp.c
> index bc11b1ec59ac..98092dcc1870 100644
> --- a/drivers/infiniband/sw/rxe/rxe_odp.c
> +++ b/drivers/infiniband/sw/rxe/rxe_odp.c
> @@ -545,7 +545,7 @@ static int rxe_ib_advise_mr_prefetch(struct ib_pd *ibpd,
>  		work->frags[i].mr = mr;
>  	}
>  
> -	queue_work(system_unbound_wq, &work->work);
> +	rxe_queue_work(&work->work);
>  
>  	return 0;
>  
> diff --git a/drivers/infiniband/sw/rxe/rxe_task.c b/drivers/infiniband/sw/rxe/rxe_task.c
> index f522820b950c..4385137eb4d7 100644
> --- a/drivers/infiniband/sw/rxe/rxe_task.c
> +++ b/drivers/infiniband/sw/rxe/rxe_task.c
> @@ -10,7 +10,8 @@ static struct workqueue_struct *rxe_wq;
>  
>  int rxe_alloc_wq(void)
>  {
> -	rxe_wq = alloc_workqueue("rxe_wq", WQ_UNBOUND, WQ_MAX_ACTIVE);
> +	rxe_wq = alloc_workqueue("rxe_wq", WQ_UNBOUND | WQ_MEM_RECLAIM,

Why did you add WQ_MEM_RECLAIM flag? rxe_ib_advise_mr_prefetch() doesn't
perform any memory reclaim.

Thanks