APPLIED [FH Azure]: [PATCH 0/3] [FHI:linux-azure] CONFIG_RT_GROUP_SCHED=y

[Tim Gardner]

Applied to Focal azure/master-next, Hirsute azure/master-next. Thanks.

Waiting for Impish to transition to 5.13 before setting this config option.

-rtg

On 8/5/21 8:54 AM, Tim Gardner wrote:
> BugLink: https://bugs.launchpad.net/bugs/1939024
> 
> [Impact]
> 
> Microsoft has requested that CONFIG_RT_GROUP_SCHED be enabled. This option has
> no discernible runtime impact in the default case. As quoted from research
> performed by Colin King, "I ran some synthetic stress-ng throughput and
> latency tests with and without CONFIG_RT_GROUP_SCHED on CONFIG_RT_GROUP_SCHED.
> I don't see enough variation in the throughput or latency to warrant any concern
> about enabling this option. We have quite a bit of small jitter on the results,
> but overall the kernel results are similar enough to make me feel OK to enable
> this option for Focal."
> 
> [Fix]
> 
> CONFIG_RT_GROUP_SCHED=y
> 
> [Test Case]
> 
> Microsoft has tested this option using kernels at
> https://kernel.ubuntu.com/~rtg/azure-rt-group-sched-sf00314473/. The customer
> requesting this config option verified that it satisfied their requirements.
> Microsft also determined that there were no performance regressions for the default
> case, i.e., when no RT priority threads were created.
> 
> [Where problems could occur]
> 
> Adding options to the scheduler could impact work loads that we have yet to observe.
> 
> [Other Info]
> 
> SF: 00314473
> 

-- 
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Tim Gardner
Canonical, Inc