Re: [PATCH V2] x86/split_lock: Add sysctl to control the misery mode

Guilherme G. Piccoli
2022-10-15T00:19:58Z

On 14/10/2022 15:26, Luck, Tony wrote:
> Looks reasonable.
>
> Are these games multi-threaded with split locks happening on multiple CPUs in parallel?
> If they are, then skipping both the 10ms delay and the serialization is needed.
>
> But if split locks are only from one CPU at a time, then possibly it would have
> been enough to just have this mitigation skip the:
>
> + if (msleep_interruptible(10) > 0)
> + return;
>
> Maybe best not to second guess. You have left the default as "mitigation on",
> so I'm happy.
>
> -Tony

Hi Tony, thanks for your review!

Some games are indeed multi-threaded, so as you said, I think it's
better if we skip the whole thing when the sysctl is off - a kind of
fallback to the old "warn" mode before the misery was added heh

Cheers,

Guilherme