Re: [PATCH RFC] iw_cxgb4: drop check - dead code

From: Jason Gunthorpe
Date: Wed Jan 23 2019 - 13:30:14 EST


On Sun, Jan 20, 2019 at 02:27:13AM +0100, Nicholas Mc Guire wrote:
> The kmalloc is called with | __GFP_NOFAIL so there is no point in
> checking the return value - it either returns valid storage or it would
> hang/terminate there. But it is not possible to say if the use of
> __GFP_NOFAIL is really needed and the check should be removed or
> vice-versa (use of __GFP_NOFAIL should be only in exceptional
> cases as I understand it and alloc_srq_queue() is called in quite
> a few places)
> In either way it would need fixing.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@xxxxxxxxx>
> Fixes: 6a0b6174d35a ("rdma/cxgb4: Add support for kernel mode SRQ's")
> ---

Steve? It seems weird to have NOFAIL and then have an error unwind
path, what is the deal here?

> diff --git a/drivers/infiniband/hw/cxgb4/qp.c b/drivers/infiniband/hw/cxgb4/qp.c
> index 917ce5c..c2a12ba 100644
> --- a/drivers/infiniband/hw/cxgb4/qp.c
> +++ b/drivers/infiniband/hw/cxgb4/qp.c
> @@ -2597,8 +2597,6 @@ static int alloc_srq_queue(struct c4iw_srq *srq, struct c4iw_dev_ucontext *uctx,
> wr_len = sizeof(*res_wr) + sizeof(*res);
>
> skb = alloc_skb(wr_len, GFP_KERNEL | __GFP_NOFAIL);
> - if (!skb)
> - goto err_free_queue;
> set_wr_txq(skb, CPL_PRIORITY_CONTROL, 0);
>
> res_wr = (struct fw_ri_res_wr *)__skb_put(skb, wr_len);
> --
> 2.1.4
>