[PATCH] powerpc/perf: Fix cycles/instructions as PM_CYC/PM_INST_CMPL in power10

Paul A. Clarke pc at us.ibm.com
Fri Jul 9 01:43:52 AEST 2021


On Thu, Jul 08, 2021 at 10:56:57PM +1000, Nicholas Piggin wrote:
> Excerpts from Athira Rajeev's message of July 7, 2021 4:39 pm:
> > From: Athira Rajeev <atrajeev at linux.vnet.ibm.cm>
> > 
> > Power10 performance monitoring unit (PMU) driver uses performance
> > monitor counter 5 (PMC5) and performance monitor counter 6 (PMC6)
> > for counting instructions and cycles. Event used for cycles is
> > PM_RUN_CYC and instructions is PM_RUN_INST_CMPL. But counting of these
> > events in wait state is controlled by the CC56RUN bit setting in
> > Monitor Mode Control Register0 (MMCR0). If the CC56RUN bit is not
> > set, PMC5/6 will not count when CTRL[RUN] is zero.
> 
> What's the acutal bug here, can you explain a bit more? I thought
> PM_RUN_CYC is supposed to be gated by the runlatch.

Would this renaming break compatibility with existing tools that
presume PM_RUN_CYC and PM_RUN_INST_CMPL exist generically?

PC


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