On Mon, May 22, 2017 at 12:26 PM, Sebastian Andrzej Siewior
<bige...@linutronix.de> wrote:
> Since commit 217f69743681 ("net: busy-poll: allow preemption in
> sk_busy_loop()") there is an explicit do_softirq() invocation after
> local_bh_enable() has been invoked.
> I don't understand why we need this because local_bh_enable() will
> invoke do_softirq() once the softirq counter reached zero and we have
> softirq-related work pending.
>
> Signed-off-by: Sebastian Andrzej Siewior <bige...@linutronix.de>
> ---
> net/core/dev.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index fca407b4a6ea..e84eb0ec5529 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -5199,8 +5199,6 @@ static void busy_poll_stop(struct napi_struct *napi,
> void *have_poll_lock)
> if (rc == BUSY_POLL_BUDGET)
> __napi_schedule(napi);
> local_bh_enable();
> - if (local_softirq_pending())
> - do_softirq();
> }
preemption is disabled.
Look at netif_rx_ni() for a similar construct.
What exact problem do you have with existing code, that is worth
adding this change ?
Thanks.
