On 12/01/2015 10:43 PM, Michael S. Tsirkin wrote:> On Tue, Dec 01, 2015 at 01:17:49PM +0800, Jason Wang wrote: >> >> On 11/30/2015 06:44 PM, Michael S. Tsirkin wrote: >>> On Wed, Nov 25, 2015 at 03:11:29PM +0800, Jason Wang wrote: >>>>> This patch tries to poll for new added tx buffer or socket receive >>>>> queue for a while at the end of tx/rx processing. The maximum time >>>>> spent on polling were specified through a new kind of vring ioctl. >>>>> >>>>> Signed-off-by: Jason Wang <jasowang at redhat.com> >>> One further enhancement would be to actually poll >>> the underlying device. This should be reasonably >>> straight-forward with macvtap (especially in the >>> passthrough mode). >>> >>> >> Yes, it is. I have some patches to do this by replacing >> skb_queue_empty() with sk_busy_loop() but for tap. > We probably don't want to do this unconditionally, though. > >> Tests does not show >> any improvement but some regression. > Did you add code to call sk_mark_napi_id on tap then? > sk_busy_loop won't do anything useful without.Yes I did. Probably something wrong elsewhere.> >> Maybe it's better to test macvtap. > Same thing ... >
Michael S. Tsirkin
2015-Dec-02 12:36 UTC
[PATCH net-next 3/3] vhost_net: basic polling support
On Wed, Dec 02, 2015 at 01:04:03PM +0800, Jason Wang wrote:> > > On 12/01/2015 10:43 PM, Michael S. Tsirkin wrote: > > On Tue, Dec 01, 2015 at 01:17:49PM +0800, Jason Wang wrote: > >> > >> On 11/30/2015 06:44 PM, Michael S. Tsirkin wrote: > >>> On Wed, Nov 25, 2015 at 03:11:29PM +0800, Jason Wang wrote: > >>>>> This patch tries to poll for new added tx buffer or socket receive > >>>>> queue for a while at the end of tx/rx processing. The maximum time > >>>>> spent on polling were specified through a new kind of vring ioctl. > >>>>> > >>>>> Signed-off-by: Jason Wang <jasowang at redhat.com> > >>> One further enhancement would be to actually poll > >>> the underlying device. This should be reasonably > >>> straight-forward with macvtap (especially in the > >>> passthrough mode). > >>> > >>> > >> Yes, it is. I have some patches to do this by replacing > >> skb_queue_empty() with sk_busy_loop() but for tap. > > We probably don't want to do this unconditionally, though. > > > >> Tests does not show > >> any improvement but some regression. > > Did you add code to call sk_mark_napi_id on tap then? > > sk_busy_loop won't do anything useful without. > > Yes I did. Probably something wrong elsewhere.Is this for guest-to-guest? the patch to do napi for tap is still not upstream due to minor performance regression. Want me to repost it?> > > >> Maybe it's better to test macvtap. > > Same thing ... > >
On 12/02/2015 08:36 PM, Michael S. Tsirkin wrote:> On Wed, Dec 02, 2015 at 01:04:03PM +0800, Jason Wang wrote: >> >> On 12/01/2015 10:43 PM, Michael S. Tsirkin wrote: >>> On Tue, Dec 01, 2015 at 01:17:49PM +0800, Jason Wang wrote: >>>> On 11/30/2015 06:44 PM, Michael S. Tsirkin wrote: >>>>> On Wed, Nov 25, 2015 at 03:11:29PM +0800, Jason Wang wrote: >>>>>>> This patch tries to poll for new added tx buffer or socket receive >>>>>>> queue for a while at the end of tx/rx processing. The maximum time >>>>>>> spent on polling were specified through a new kind of vring ioctl. >>>>>>> >>>>>>> Signed-off-by: Jason Wang <jasowang at redhat.com> >>>>> One further enhancement would be to actually poll >>>>> the underlying device. This should be reasonably >>>>> straight-forward with macvtap (especially in the >>>>> passthrough mode). >>>>> >>>>> >>>> Yes, it is. I have some patches to do this by replacing >>>> skb_queue_empty() with sk_busy_loop() but for tap. >>> We probably don't want to do this unconditionally, though. >>> >>>> Tests does not show >>>> any improvement but some regression. >>> Did you add code to call sk_mark_napi_id on tap then? >>> sk_busy_loop won't do anything useful without. >> Yes I did. Probably something wrong elsewhere. > Is this for guest-to-guest?Nope. Like you said below, since it requires NAPI so it was external host to guest.> the patch to do napi > for tap is still not upstream due to minor performance > regression. Want me to repost it?Sure, I've played this a little bit in the past too.> >>>> Maybe it's better to test macvtap. >>> Same thing ... >>> > -- > To unsubscribe from this list: send the line "unsubscribe kvm" in > the body of a message to majordomo at vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
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