Re: [PATCH net 00/15] netpoll: avoid capture effects for NAPI drivers

[Eric Dumazet]

On Mon, Sep 24, 2018 at 12:31 PM Song Liu <songliubrav...@fb.com> wrote:

> This triggers dev_watchdog() on a simple netperf TCP_RR on bnxt (I haven't
> tested other drivers yet).
>
> I guess this is because NAPI_STATE_SCHED is set when poll_one_napi() calls
> napi->poll(). And then cleared by napi->poll().

Which part of napi->poll() could possibly clear NAPI_STATE_SCHED when
called by netpoll ?

AFAIK, napi_complete_done() should exit early (before having a chance
to clear NAPI_STATE_SCHED)
because of :

if (unlikely(n->state & (NAPIF_STATE_NPSVC | NAPIF_STATE_IN_BUSY_POLL)))
     return false;

Thanks !