Re: [PATCH 25/32] sched: introduce the finish_arch_pre_lock_switch() scheduler hook

[Peter Zijlstra]

On Thu, Apr 28, 2016 at 09:43:31PM -0700, David Carrillo-Cisneros wrote:
> This hook allows architecture specific code to be called at the end of
> the task switch and after perf_events' context switch but before the
> scheduler lock is released.
> 
> The specific use case in this series is to avoid multiple writes to a slow
> MSR until all functions which modify such register in task switch have
> finished.

Yeah, no. This really need way more justification. Why can't you use the
regular perf sched-in stuff for CQM?