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[Bug 1521053] Re: Network Performance dropping between vms on different location in Azure


I built a Vivid test kernel with a cherry pick of commit 0d158852a.  The
test kernel can be downloaded from:


Can you test this kernel and see if it resolves this bug?  If it does,
we can submit an SRU request for that commit.

Thanks in advance!

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  Network Performance dropping between vms on different location in

Status in linux package in Ubuntu:
  In Progress
Status in linux source package in Vivid:
  In Progress

Bug description:

  Ubuntu VM in Azure has network performance issue when check by using netcat&nload
  Normal bandwidth is 50MB/s ~ 100MB/s, but it's 0.3MB/s when dropping happens


  Upstream development
  0d158852a8089099a6959ae235b20f230871982f ("hv_netvsc: Clean up two unused variables")

  It's affected over 3.19.0-28-generic (vivid)

  With this commit, I confirmed that the problem has gone by the


  This is only for Azure service.

  Make 2 vms on North Europe,  West Europe and run below test script


   while true; do netcat -l 8080 < /dev/zero; done;

   nload -u M eth0 ( need nload pkg )


   for i in {1..1000} 
    timeout 30s nc NE_HOST 8080 > /dev/null 

  Network performance dropping can be seen frequently

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