Hi All,
So this patch, which I already submitted a while ago and back then it got one comment from Chris Wilson:
Basically you want a limit on the frequency of ... pcode access? As presented, you ultimately do not trust any write and the only solution is to disable all writes. No RPS whatsoever, run at max and hope rc6 works (maybe even decrease the rc6 threshold).
One of the ideas we floated was moving the pcode access to a worker and ratelimiting the updates.
Has finally seen some testing by users affected by the infamous "intel_idle.max_cstate=1 required to prevent crashes" bug: https://bugzilla.kernel.org/show_bug.cgi?id=109051
And so far the reports are that it does help to make the users stable for 2/3 users and it not being effective for 1/3 users.
Now that we've some test results, I believe that it is worthwhile to get this simple patch mainlined, hence this re-submission.
Regards,
Hans