Uncore Manual

Uncore Performance Monitoring
Power Control (PCU) Performance Monitoring
128 Reference Number: 329468-002
FREQ_MAX_LIMIT_THERMAL_CYCLES
• Title: Thermal Strongest Upper Limit Cycles
• Category: FREQ_MAX_LIMIT Events
• Event Code: 0x04
• Max. Inc/Cyc:. 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles when thermal conditions are the upper limit on frequency.
This is related to the THERMAL_THROTTLE CYCLES_ABOVE_TEMP event, which always counts cycles
when we are above the thermal temperature. This event (STRONGEST_UPPER_LIMIT) is sampled at
the output of the algorithm that determines the actual frequency, while THERMAL_THROTTLE looks
at the input.
FREQ_MAX_OS_CYCLES
• Title: OS Strongest Upper Limit Cycles
• Category: FREQ_MAX_LIMIT Events
• Event Code: 0x06
• Max. Inc/Cyc:. 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles when the OS is the upper limit on frequency.
• NOTE: Essentially, this event says the OS is getting the frequency it requested.
FREQ_MAX_POWER_CYCLES
• Title: Power Strongest Upper Limit Cycles
• Category: FREQ_MAX_LIMIT Events
• Event Code: 0x05
• Max. Inc/Cyc:. 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles when power is the upper limit on frequency.
FREQ_MIN_IO_P_CYCLES
• Title: IO P Limit Strongest Lower Limit Cycles
• Category: FREQ_MIN_LIMIT Events
• Event Code: 0x61
• Max. Inc/Cyc:. 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles when IO P Limit is preventing us from dropping the fre-
quency lower. This algorithm monitors the needs to the IO subsystem on both local and remote
sockets and will maintain a frequency high enough to maintain good IO BW. This is necessary for
when all the IA cores on a socket are idle but a user still would like to maintain high IO Bandwidth.
FREQ_MIN_PERF_P_CYCLES
• Title: Perf P Limit Strongest Lower Limit Cycles
• Category: FREQ_MIN_LIMIT Events
• Event Code: 0x02
• Extra Select Bit: Y
• Max. Inc/Cyc:. 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles when Perf P Limit is preventing us from dropping the fre-
quency lower. Perf P Limit is an algorithm that takes input from remote sockets when determining if
a socket should drop it's frequency down. This is largely to minimize increases in snoop and remote
read latencies.