> Seems to make some progress on wakeup mitigation. Previous patch tries > to reduce the unnecessary traversal of waitqueue during rx. Attached > patch goes even further which disables rx polling during processing tx. > Please try it to see if it has any difference.
Unfortunately, this patch doesn't seem to have made a difference. I tried runs with both this patch and the previous patch applied, as well as only this patch applied for comparison (numbers from vhost thread of sending VM): 4.12 4.13 patch1 patch2 patch1+2 2.00% +3.69% +2.55% +2.81% +2.69% [...] __wake_up_sync_key In each case, the regression in throughput was still present. > And two questions: > - Is the issue existed if you do uperf between 2VMs (instead of 4VMs) Verified that the second set of guests are not actually required, I can see the regression with only 2 VMs. > - Can enable batching in the tap of sending VM improve the performance > (ethtool -C $tap rx-frames 64) I tried this, but it did not help (actually seemed to make things a little worse)
