Commits to resolve high network latency
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux-azure (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned | ||
Xenial |
Fix Released
|
Undecided
|
Marcelo Cerri | ||
Bionic |
Invalid
|
Undecided
|
Unassigned | ||
linux-azure-4.15 (Ubuntu) |
Fix Released
|
Undecided
|
Unassigned | ||
Xenial |
Invalid
|
Undecided
|
Unassigned | ||
Bionic |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
An issue has been identified with the NETVSC driver on Azure VMs. This issues has been fixed by four patches, which are available in the mainline kernel.
The issues is the following:
Outgoing traffic is sent from the guest to the Azure host over multiple parallel channels. The issue causes the traffic to be unevenly balanced across the channels, which results in a physical CPU on the Azure host becoming overloaded. In turn, the network traffic on the overloaded channel experiences significantly higher latency. This higher latency is causing issues for customers.
This issue is resolved by the following four mainline commits:
71f21959dd55 ("hv_netvsc: Fix offset usage in netvsc_
171c1fd98df3 ("hv_netvsc: Fix send_table offset in case of a host bug")
c39ea5cba5a2 ("hv_netvsc: Fix tx_table init in rndis_set_
b0689faa8efc ("hv_netvsc: Fix unwanted rx_table reset")
These four commits have been submitted to upstream stable.
We would like to request these commits in Azure kernels for Xenial and Bionic
CVE References
Changed in linux-azure (Ubuntu Xenial): | |
assignee: | nobody → Marcelo Cerri (mhcerri) |
Changed in linux-azure (Ubuntu Xenial): | |
status: | In Progress → Fix Committed |
Changed in linux-azure-4.15 (Ubuntu Xenial): | |
status: | New → Invalid |
Changed in linux-azure-4.15 (Ubuntu Bionic): | |
status: | New → Fix Committed |
Changed in linux-azure (Ubuntu Bionic): | |
status: | New → Invalid |
Changed in linux-azure-4.15 (Ubuntu): | |
status: | New → Fix Released |
Changed in linux-azure (Ubuntu): | |
status: | New → Fix Released |
The 5.3 azure kernel in proposed already has all the required commits
linux-azure (5.3.0-1019.20) - proposed
- hv_netvsc: Fix offset usage in netvsc_send_table()
- hv_netvsc: Fix send_table offset in case of a host bug
linux-azure (5.3.0-1014.15)
- hv_netvsc: Fix unwanted rx_table reset
linux-azure (5.3.0-1013.14) subchannel( )
- hv_netvsc: Fix tx_table init in rndis_set_
We will move the bionic:linux-azure to 5.3, so there's no need to fix it on 5.0.