Messages in this thread Patch in this message | | | Subject | Re: Long delays creating a netns after deleting one (possibly RCU related) | From | Eric Dumazet <> | Date | Mon, 14 Nov 2016 15:09:27 -0800 |
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On Mon, 2016-11-14 at 14:46 -0800, Eric Dumazet wrote: > On Mon, 2016-11-14 at 16:12 -0600, Eric W. Biederman wrote: > > > synchronize_rcu_expidited is not enough if you have multiple network > > devices in play. > > > > Looking at the code it comes down to this commit, and it appears there > > is a promise add rcu grace period combining by Eric Dumazet. > > > > Eric since people are hitting noticable stalls because of the rcu grace > > period taking a long time do you think you could look at this code path > > a bit more? > > > > commit 93d05d4a320cb16712bb3d57a9658f395d8cecb9 > > Author: Eric Dumazet <edumazet@google.com> > > Date: Wed Nov 18 06:31:03 2015 -0800 > > Absolutely, I will take a loop asap.
The worst offender should be fixed by the following patch.
busy poll needs to poll the physical device, not a virtual one...
diff --git a/include/net/gro_cells.h b/include/net/gro_cells.h index d15214d673b2e8e08fd6437b572278fb1359f10d..2a1abbf8da74368cd01adc40cef6c0644e059ef2 100644 --- a/include/net/gro_cells.h +++ b/include/net/gro_cells.h @@ -68,6 +68,9 @@ static inline int gro_cells_init(struct gro_cells *gcells, struct net_device *de struct gro_cell *cell = per_cpu_ptr(gcells->cells, i); __skb_queue_head_init(&cell->napi_skbs); + + set_bit(NAPI_STATE_NO_BUSY_POLL, &cell->napi.state); + netif_napi_add(dev, &cell->napi, gro_cell_poll, 64); napi_enable(&cell->napi); }
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