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

Anju T Sudhakar anju at linux.vnet.ibm.com
Fri Mar 29 16:27:14 AEDT 2019

Hi Stewart,

On 3/29/19 10:23 AM, Stewart Smith wrote:
> 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.

Sorry, I've cc'ed stable by mistake. I informed Vasant on this.



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