Re: [PATCH net] net: sched: check netif_xmit_frozen_or_stopped() in sch_direct_xmit()

On May 29, 2018, at 7:02 AM, David Miller [off-list ref] wrote:

From: Song Liu <redacted>
Date: Fri, 25 May 2018 11:11:44 -0700

quoted

Summary:

At the end of sch_direct_xmit(), we are in the else path of
!dev_xmit_complete(ret), which means ret == NETDEV_TX_OK. The following
condition will always fail and netif_xmit_frozen_or_stopped() is not
checked at all.

   if (ret && netif_xmit_frozen_or_stopped(txq))
        return false;

In this patch, this condition is fixed as:

   if (netif_xmit_frozen_or_stopped(txq))
        return false;

and further simplifies the code as:

   return !netif_xmit_frozen_or_stopped(txq);

Fixes: 29b86cdac00a ("net: sched: remove remaining uses for qdisc_qlen in xmit path")
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Song Liu <redacted>

I expect a new version of this patch which removes the test entirely.

The new version of it is here: http://patchwork.ozlabs.org/patch/921708/

Thanks,
Song