linux-kernel - Re: [PATCH] RDMA/hfi1: Switch to kvfree

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Message-ID: <YbpGWpskiByQNcJO@pc638.lan>
Date:   Wed, 15 Dec 2021 20:47:38 +0100
From:   Uladzislau Rezki <urezki@...il.com>
To:     linux-rdma@...r.kernel.org, Jason Gunthorpe <jgg@...dia.com>,
        Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>
Cc:     LKML <linux-kernel@...r.kernel.org>, RCU <rcu@...r.kernel.org>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Michal Hocko <mhocko@...e.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Daniel Axtens <dja@...ens.net>,
        Frederic Weisbecker <frederic@...nel.org>,
        Neeraj Upadhyay <neeraju@...eaurora.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "Theodore Y . Ts'o" <tytso@....edu>,
        Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...ymobile.com>,
        Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>
Subject: Re: [PATCH] RDMA/hfi1: Switch to kvfree_rcu() API

On Wed, Dec 15, 2021 at 12:18:44PM +0100, Uladzislau Rezki (Sony) wrote:
> Instead of invoking a synchronize_rcu() to free a pointer
> after a grace period we can directly make use of new API
> that does the same but in more efficient way.
> 
> TO: linux-rdma@...r.kernel.org
> TO: Jason Gunthorpe <jgg@...dia.com>
> TO: Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>
> Acked-by: Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@...il.com>
> ---
>  drivers/infiniband/hw/hfi1/sdma.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
> index f07d328689d3..7264a35e8f4c 100644
> --- a/drivers/infiniband/hw/hfi1/sdma.c
> +++ b/drivers/infiniband/hw/hfi1/sdma.c
> @@ -1292,8 +1292,7 @@ void sdma_clean(struct hfi1_devdata *dd, size_t num_engines)
>  	sdma_map_free(rcu_access_pointer(dd->sdma_map));
>  	RCU_INIT_POINTER(dd->sdma_map, NULL);
>  	spin_unlock_irq(&dd->sde_map_lock);
> -	synchronize_rcu();
> -	kfree(dd->per_sdma);
> +	kvfree_rcu(dd->per_sdma);
>  	dd->per_sdma = NULL;
>  
>  	if (dd->sdma_rht) {
> -- 
> 2.30.2
> 
+ linux-rdma@...r.kernel.org
+ Jason Gunthorpe <jgg@...dia.com>
+ Mike Marciniszyn <mike.marciniszyn@...nelisnetworks.com>

--
Vlad Rezki