Commit 9684f5e7 authored Jul 11, 2018 by Magnus Karlsson Committed by Daniel Borkmann Jul 13, 2018

xsk: do not return EAGAIN from sendmsg when completion queue is full



This patch stops returning EAGAIN in TX copy mode when the completion
queue is full as zero-copy does not do this. Instead this situation
can be detected by comparing the head and tail pointers of the
completion queue in both modes. In any case, EAGAIN was not the
correct error code here since no amount of calling sendmsg will solve
the problem. Only consuming one or more messages on the completion
queue will fix this.

With this patch, the error reporting becomes consistent between copy
mode and zero-copy mode.

Fixes: 35fcde7f ("xsk: support for Tx")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

parent 509d7648

net/xdp/xsk.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -233,10 +233,8 @@ static int xsk_generic_xmit(struct sock sk, struct msghdr m,
		goto out;
		}

		if (xskq_reserve_addr(xs->umem->cq)) {
		err = -EAGAIN;
		if (xskq_reserve_addr(xs->umem->cq))
		goto out;
		}

		len = desc.len;
		if (unlikely(len > xs->dev->mtu)) {

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