On 11/20/2018 01:17 PM, Paolo Abeni wrote: > Eric noted that with UDP GRO and napi timeout, we could keep a single
NAPI, else you're simply inconsistent. > UDP packet inside the GRO hash forever, if the related NAPI instance > calls napi_gro_complete() at an higher frequency than the napi timeout. NAPI. > Willem noted that even TCP packets could be trapped there, till the > next retransmission. > This patch tries to address the issue, flushing the oldest packets before > scheduling the NAPI timeout. The rationale is that such a timeout should be > well below a jiffy and we are not flushing packets eligible for sane GRO. > > Reported-by: Eric Dumazet <[email protected]> > Signed-off-by: Paolo Abeni <[email protected]> > --- > Sending as RFC, as I fear I'm missing some relevant pieces. > Also I'm unsure if this should considered a fixes for "udp: implement > GRO for plain UDP sockets." or for "net: gro: add a per device gro flush > timer" > --- > net/core/dev.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/net/core/dev.c b/net/core/dev.c > index 5927f6a7c301..5cc4c4961869 100644 > --- a/net/core/dev.c > +++ b/net/core/dev.c > @@ -5975,11 +5975,14 @@ bool napi_complete_done(struct napi_struct *n, int > work_done) > if (work_done) > timeout = n->dev->gro_flush_timeout; > > + /* When the NAPI instance uses a timeout, we still need to > + * someout bound the time packets are keept in the GRO layer Somehow? > + * under heavy traffic > + */ > + napi_gro_flush(n, !!timeout); > if (timeout) > hrtimer_start(&n->timer, ns_to_ktime(timeout), > HRTIMER_MODE_REL_PINNED); > - else > - napi_gro_flush(n, false); > } > if (unlikely(!list_empty(&n->poll_list))) { > /* If n->poll_list is not empty, we need to mask irqs */ MBR, Sergei
