From: Jason Gunthorpe <jgg@nvidia.com>
To: Bob Pearson <rpearsonhpe@gmail.com>
Cc: zyjzyj2000@gmail.com, linux-rdma@vger.kernel.org
Subject: Re: [PATCH for-next 1/6] RDMA/rxe: Make rxe_alloc() take pool lock
Date: Wed, 20 Oct 2021 20:16:53 -0300 [thread overview]
Message-ID: <20211020231653.GA28428@nvidia.com> (raw)
In-Reply-To: <20211010235931.24042-2-rpearsonhpe@gmail.com>
On Sun, Oct 10, 2021 at 06:59:26PM -0500, Bob Pearson wrote:
> In rxe there are two separate pool APIs for creating a new object
> rxe_alloc() and rxe_alloc_locked(). Currently they are identical.
> Make rxe_alloc() take the pool lock which is in line with the other
> APIs in the library.
>
> Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
> drivers/infiniband/sw/rxe/rxe_pool.c | 21 ++++-----------------
> 1 file changed, 4 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> index ffa8420b4765..7a288ebacceb 100644
> +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> @@ -352,27 +352,14 @@ void *rxe_alloc_locked(struct rxe_pool *pool)
>
> void *rxe_alloc(struct rxe_pool *pool)
> {
> - struct rxe_type_info *info = &rxe_type_info[pool->type];
> - struct rxe_pool_entry *elem;
> + unsigned long flags;
> u8 *obj;
>
> - if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
> - goto out_cnt;
> -
> - obj = kzalloc(info->size, GFP_KERNEL);
> - if (!obj)
> - goto out_cnt;
> -
> - elem = (struct rxe_pool_entry *)(obj + info->elem_offset);
> -
> - elem->pool = pool;
> - kref_init(&elem->ref_cnt);
> + write_lock_irqsave(&pool->pool_lock, flags);
> + obj = rxe_alloc_locked(pool);
> + write_unlock_irqrestore(&pool->pool_lock, flags);
But why? This just makes a GFP_KERNEL allocation into a GFP_ATOMIC
allocation, which is bad.
Jason
next prev parent reply other threads:[~2021-10-20 23:16 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-10 23:59 [PATCH for-next 0/6] RDMA/rxe: Fix potential races Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 1/6] RDMA/rxe: Make rxe_alloc() take pool lock Bob Pearson
2021-10-20 23:16 ` Jason Gunthorpe [this message]
2021-10-21 17:46 ` Bob Pearson
2021-10-25 12:43 ` Jason Gunthorpe
2021-10-25 18:48 ` Robert Pearson
2021-10-10 23:59 ` [PATCH for-next 2/6] RDMA/rxe: Copy setup parameters into rxe_pool Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 3/6] RDMA/rxe: Save object pointer in pool element Bob Pearson
2021-10-20 23:20 ` Jason Gunthorpe
2021-10-21 17:21 ` Bob Pearson
2021-10-25 15:40 ` Jason Gunthorpe
2021-10-10 23:59 ` [PATCH for-next 4/6] RDMA/rxe: Combine rxe_add_index with rxe_alloc Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 5/6] RDMA/rxe: Combine rxe_add_key " Bob Pearson
2021-10-10 23:59 ` [PATCH for-next 6/6] RDMA/rxe: Fix potential race condition in rxe_pool Bob Pearson
2021-10-20 23:23 ` Jason Gunthorpe
2021-10-12 6:34 ` [PATCH for-next 0/6] RDMA/rxe: Fix potential races Leon Romanovsky
2021-10-12 20:19 ` Bob Pearson
2021-10-19 13:07 ` Leon Romanovsky
2021-10-19 16:35 ` Bob Pearson
2021-10-19 18:43 ` Jason Gunthorpe
2021-10-19 22:51 ` Bob Pearson
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