APPLIED: [PATCH 0/2][lunar/jammy linux-azure] Azure: MANA: Fix doorbell access for receives

Tim Gardner tim.gardner at canonical.com
Thu Jul 13 18:04:07 UTC 2023


On 7/12/23 12:50 PM, Tim Gardner wrote:
> 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.
> 
> 
> 
Applied to llunar/jammy linux-azure:master-next. Thanks.

-rtg
-- 
-----------
Tim Gardner
Canonical, Inc




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