Re: [PATCH] IB/mlx4: Allocation of CQ resize structure doesn't need to be atomic

On Thu, Jul 28, 2016 at 09:58:43PM -0700, Roland Dreier wrote:

From: Roland Dreier <redacted>

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 <redacted>

Thanks,
Reviewed-by: Leon Romanovsky <leonro-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>