[PATCH 0/2][lunar/jammy linux-azure] Azure: MANA: Fix doorbell access for receives
Tim Gardner
tim.gardner at canonical.com
Wed Jul 12 18:50:57 UTC 2023
BugLink: https://bugs.launchpad.net/bugs/2027615
SRU Justification
[Impact]
It's inefficient to ring the doorbell page every time a WQE is posted to
the received queue. Excessive MMIO writes result in CPU spending more
time waiting on LOCK instructions (atomic operations), resulting in
poor scaling performance.
[Test Plan]
MSFT tested. Performance improved substantially.
[Regression Potential]
The MANA receive queue could stop.
[Other Info]
SF: #00363437
These 2 patches have been submitted for upstream inclusion. I expect
them to eventually come down via stable updates.
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