Re: [Xen-devel] [PATCH] sched/credit: avoid priority boost for capped domains when unpark

[Lars Kurth <lars.kurth.xen@xxxxxxxxx>]

> On 3 May 2019, at 10:48, Dario Faggioli <dfaggioli@xxxxxxxx> wrote:
> 
> On Fri, 2019-05-03 at 15:38 +0000, Eslam Elnikety wrote:
>> When unpausing a capped domain, the scheduler currently clears the
>> CSCHED_FLAG_VCPU_PARKED flag before vcpu_wake(). This, in turn,
>> causes the
>> vcpu_wake to set CSCHED_PRI_TS_BOOST, resulting in an unfair credit
>> boost. The
>> comment around the changed lines already states that clearing the
>> flag should
>> happen AFTER the unpause. This bug was introduced in commit
>> be650750945
>> "credit1: Use atomic bit operations for the flags structure".
>> 
>> Original patch author credit: Xi Xiong.
>> 
> Mmm... I'm not an expert of these things, but doesn't this means we
> need a "Signed-off-by: Xi Xiong <xxx@xxxxxxx>" then? Cc-ing Lars...

As far as I can tell from a quick search on xen-devel@ Xi Xiong is or 
was an Amazon employee so a signed-off-by is not strictly necessary
but you may want to say something like.

Original patch author credit: Xi Xiong of Amazon

Lars

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