Hi Stewart, On 08/10/2015 05:53 AM, Stewart Smith wrote: > Shilpasri G Bhat <shilpa.b...@linux.vnet.ibm.com> writes: >> Add OPAL_MSG_OCC message definition to opal_message_type to receive >> OCC events like reset, load and throttled. Host performance can be >> affected when OCC is reset or OCC throttles the max Pstate. >> We can register to opal_message_notifier to receive OPAL_MSG_OCC type >> of message and report it to the userspace so as to keep the user >> informed about the reason for a performance drop in workloads. >> >> The reset and load OCC events are notified to kernel when FSP sends >> OCC_RESET and OCC_LOAD commands. Both reset and load messages are >> sent to kernel on successful completion of reset and load operation >> respectively. > > How is this done on OpenPower systems? Explanation involving just what > OPAL does is likely better, rather than explaining in context of FSP, > which Linux has no real knowledge of (OPAL provides all abstraction of > it). >
In OpenPower systems, opal will only send OCC throttled event. OCC reset and load messages are not sent to kernel. How about the following git log message? Add OPAL_MSG_OCC message definition to opal_message_type to receive OCC events like reset, load and throttled. Host performance can be affected when OCC is reset or OCC throttles the max Pstate. We can register to opal_message_notifier to receive OPAL_MSG_OCC type of message and report it to the userspace so as to keep the user informed about the reason for a performance drop in workloads. Opal will send reset and load events to kernel on successful completion of reset and load operation of OCC. During this duration the cpu frequency will be throttled until OCC is started. Opal will send a throttle message during the OCC reset-cycle to indicate that OCC is active. Opal will send throttle message to kernel when OCC is active to indicate that the Pmax of the chip is reduced. The chip_id and throttle reason for reducing Pmax is queued along with the message. Thanks and Regards, Shilpa _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
