Ubuntu
linux-azure-4.15 package

  1. Bug #1924314
  2. Comment #0

Comment 0 for bug 1924314

Revision history for this message
Tim Gardner (timg-tpi) wrote :

[SRU Justification]

[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.