** Also affects: linux-azure-4.15 (Ubuntu)
   Importance: Undecided
       Status: New

** Changed in: linux-azure-4.15 (Ubuntu Bionic)
       Status: New => In Progress

** Changed in: linux-azure-4.15 (Ubuntu Bionic)
   Importance: Undecided => Medium

** Changed in: linux-azure-4.15 (Ubuntu Bionic)
     Assignee: (unassigned) => Tim Gardner (timg-tpi)

** Description changed:

  [SRU Justification]
+ 
+ SF#00308239
  
  [Impact]
  A soft lockup is happening to Azure cloud customers due to a bug in 
netvsc_poll.
  
  Ubuntu 4.15.0-1103 has CONFIG_NET_POLL_CONTROLLER=y in kernel config
  file, there is a bug in netvsc that may cause CPU lockup with
  POLL_CONTROLLER. This bug has been fixed by the following patch:
  
  commit 2a7f8c3b1d3feedee3aa319ac220cbde3725b5d5 ("hv_netvsc: remove
  ndo_poll_controller")
  
  This commit is in mainline as of 4.20-rc1.
  
  Microsoft would like to request this patch in 4.15 based Azure kernels.
  
  [Test Plan]
  Run high stress network traffic on an Azure instance.
  
  [Where problems could occur]
  There could be a decrease in performance or dropped packets due to NAPI not 
being able to keep up.

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https://bugs.launchpad.net/bugs/1924314

Title:
  netvsc may cause CPU lockup

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