[Skiboot] [PATCH v3 0/7] skiboot: OPAL support for IMC trace-mode

Stewart Smith stewart at linux.vnet.ibm.com
Fri Mar 29 15:53:53 AEDT 2019

Anju T Sudhakar <anju at linux.vnet.ibm.com> writes:
> IMC (In-Memory collection counters) is a hardware monitoring facility      
> that collects large number of hardware performance events.                 
> POWER9 support two modes for IMC which are the Accumulation mode and       
> Trace mode. In Accumulation mode, event counts are accumulated in system   
> Memory. Hypervisor then reads the posted counts periodically or when       
> requested. In IMC Trace mode, the 64 bit trace scom value is initialized
> with the event information. The CPMC*SEL and CPMC_LOAD in the trace scom, specifies
> the event to be monitored and the sampling duration. On each overflow in the
> CPMC*SEL, hardware snapshots the program counter along with event counts
> and writes into memory pointed by LDBAR. LDBAR has bits to indicate whether
> hardware is configured for accumulation or trace mode.
> Currently the event monitored for trace-mode is fixed as cycle.

I've merged the patch series to master as of
027d87475eff7d57b1bf996e4d633e880f571a22 and it's in v6.3-rc1.

I'm not sure why you CC'd stable on the ptach series though. Since it's
new function, it doesn't qualify for a stable branch.

Stewart Smith
OPAL Architect, IBM.

More information about the Skiboot mailing list