From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Xu <davidxu06@gmail.com>
Subject: reduce networking latency
Date: Wed, 24 Sep 2014 14:40:53 -0400
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Hi Michael,

I found this interesting project from KVM TODO website:

allow handling short packets from softirq or VCPU context
 Plan:
   We are going through the scheduler 3 times
   (could be up to 5 if softirqd is involved)
   Consider RX: host irq -> io thread -> VCPU thread ->
   guest irq -> guest thread.
   This adds a lot of latency.
   We can cut it by some 1.5x if we do a bit of work
   either in the VCPU or softirq context.
 Testing: netperf TCP RR - should be improved drastically
          netperf TCP STREAM guest to host - no regression

Would you mind saying more about the work either in the vCPU or
softirq context? Why it is only for short packets handling? Thanks a
lot!


Regards,

Cong