From mboxrd@z Thu Jan 1 00:00:00 1970 From: Roland Dreier Subject: [PATCH] IB/mlx4: Allocation of CQ resize structure doesn't need to be atomic Date: Thu, 28 Jul 2016 21:58:43 -0700 Message-ID: <1469768323-8093-1-git-send-email-roland@kernel.org> Return-path: Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Yishai Hadas , Doug Ledford Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-rdma@vger.kernel.org From: Roland Dreier We allocate a small tracking structure as part of mlx4_ib_resize_cq(). However, we don't need to use GFP_ATOMIC -- immediately after the allocation, we call mlx4_cq_resize(), which allocates a command mailbox with GFP_KERNEL and then sleeps on a firmware command, so we better not be in an atomic context. This actually has a real impact, because when this GFP_ATOMIC allocation fails (and GFP_ATOMIC does fail in practice) then a userspace consumer resizing a CQ will get a spurious failure that we can easily avoid. Signed-off-by: Roland Dreier --- drivers/infiniband/hw/mlx4/cq.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/hw/mlx4/cq.c b/drivers/infiniband/hw/mlx4/cq.c index 9f8b516eb2b0..d6fc8a6e8c33 100644 --- a/drivers/infiniband/hw/mlx4/cq.c +++ b/drivers/infiniband/hw/mlx4/cq.c @@ -288,7 +288,7 @@ static int mlx4_alloc_resize_buf(struct mlx4_ib_dev *dev, struct mlx4_ib_cq *cq, if (cq->resize_buf) return -EBUSY; - cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_ATOMIC); + cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_KERNEL); if (!cq->resize_buf) return -ENOMEM; @@ -316,7 +316,7 @@ static int mlx4_alloc_resize_umem(struct mlx4_ib_dev *dev, struct mlx4_ib_cq *cq if (ib_copy_from_udata(&ucmd, udata, sizeof ucmd)) return -EFAULT; - cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_ATOMIC); + cq->resize_buf = kmalloc(sizeof *cq->resize_buf, GFP_KERNEL); if (!cq->resize_buf) return -ENOMEM; -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html