Uncore Manual

Reference Number: 329468-002 153
Uncore Performance Monitoring
Intel® QPI Link Layer Performance Monitoring
event to calculate average occupancy, or with the Flit Buffer Allocations event to track average
lifetime. This monitors HOM flits only.
RxL_OCCUPANCY_NCB
• Title: RxQ Occupancy - NCB
• Category: RXQ Events
• Event Code: 0x16
• Extra Select Bit: Y
• Max. Inc/Cyc:. 128, Register Restrictions: 0-3
• Definition: Accumulates the number of elements in the QPI RxQ in each cycle. Generally, when
data is transmitted across QPI, it will bypass the RxQ and pass directly to the ring interface. If
things back up getting transmitted onto the ring, however, it may need to allocate into this buffer,
thus increasing the latency. This event can be used in conjunction with the Flit Buffer Not Empty
event to calculate average occupancy, or with the Flit Buffer Allocations event to track average
lifetime. This monitors NCB flits only.
RxL_OCCUPANCY_NCS
• Title: RxQ Occupancy - NCS
• Category: RXQ Events
• Event Code: 0x17
• Extra Select Bit: Y
• Max. Inc/Cyc:. 128, Register Restrictions: 0-3
• Definition: Accumulates the number of elements in the QPI RxQ in each cycle. Generally, when
data is transmitted across QPI, it will bypass the RxQ and pass directly to the ring interface. If
things back up getting transmitted onto the ring, however, it may need to allocate into this buffer,
thus increasing the latency. This event can be used in conjunction with the Flit Buffer Not Empty
event to calculate average occupancy, or with the Flit Buffer Allocations event to track average
lifetime. This monitors NCS flits only.
Table 2-152. Unit Masks for RxL_OCCUPANCY_HOM
Extension
umask
[15:8]
Description
VN0 bxxxxxxx1 for VN0
VN1 bxxxxxx1x for VN1
Table 2-153. Unit Masks for RxL_OCCUPANCY_NCB
Extension
umask
[15:8]
Description
VN0 bxxxxxxx1 for VN0
VN1 bxxxxxx1x for VN1
Table 2-154. Unit Masks for RxL_OCCUPANCY_NCS
Extension
umask
[15:8]
Description
VN0 bxxxxxxx1 for VN0
VN1 bxxxxxx1x for VN1