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

[Leon Romanovsky <leon-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>]

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On Thu, Jul 28, 2016 at 09:58:43PM -0700, Roland Dreier wrote:
> From: Roland Dreier <roland-BHEL68pLQRGGvPXPguhicg@public.gmane.org>
> 
> 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 <roland-BHEL68pLQRGGvPXPguhicg@public.gmane.org>

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

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