On 04/28/2016 02:19 PM, Jason Wang wrote: > On 04/27/2016 07:28 PM, Michael S. Tsirkin wrote: >> > On Tue, Apr 26, 2016 at 03:35:53AM -0400, Jason Wang wrote: >>> >> We don't stop polling socket during rx processing, this will lead >>> >> unnecessary wakeups from under layer net devices (E.g >>> >> sock_def_readable() form tun). Rx will be slowed down in this >>> >> way. This patch avoids this by stop polling socket during rx >>> >> processing. A small drawback is that this introduces some overheads in >>> >> light load case because of the extra start/stop polling, but single >>> >> netperf TCP_RR does not notice any change. In a super heavy load case, >>> >> e.g using pktgen to inject packet to guest, we get about ~17% >>> >> improvement on pps: >>> >> >>> >> before: ~1370000 pkt/s >>> >> after: ~1500000 pkt/s >>> >> >>> >> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> >> > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> >> > >> > There is one other possible enhancement: we actually have the wait queue >> > lock taken in _wake_up, but we give it up only to take it again in the >> > handler. >> > >> > It would be nicer to just remove the entry when we wake >> > the vhost thread. Re-add it if required. >> > I think that something like the below would give you the necessary API. >> > Pls feel free to use it if you are going to implement a patch on top >> > doing this - that's not a reason not to include this simple patch >> > though. > Thanks, this looks useful, will give it a try. Want to try, but looks like this will result a strange API: - poll were removed automatically during wakeup, handler does not need to care about this - but handler still need to re-add the poll explicitly in the code ? _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
