Re: [net-next PATCH v2 3/4] netdev: replace napi_reschedule with napi_schedule

From: Eric Dumazet
Date: Thu Oct 05 2023 - 12:50:48 EST


On Thu, Oct 5, 2023 at 6:32 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
>
> On Thu, 5 Oct 2023 18:11:56 +0200 Eric Dumazet wrote:
> > OK, but I suspect some users of napi_reschedule() might not be race-free...
>
> What's the race you're thinking of?

This sort of thing... the race is in fl_starving() though...

diff --git a/drivers/net/ethernet/chelsio/cxgb4/sge.c
b/drivers/net/ethernet/chelsio/cxgb4/sge.c
index 98dd78551d89..b5ff2e1a9975 100644
--- a/drivers/net/ethernet/chelsio/cxgb4/sge.c
+++ b/drivers/net/ethernet/chelsio/cxgb4/sge.c
@@ -4261,7 +4261,7 @@ static void sge_rx_timer_cb(struct timer_list *t)

if (fl_starving(adap, fl)) {
rxq = container_of(fl, struct sge_eth_rxq, fl);
- if (napi_reschedule(&rxq->rspq.napi))
+ if (napi_schedule(&rxq->rspq.napi))
fl->starving++;
else
set_bit(id, s->starving_fl);