Uncore Manual

Reference Number: 329468-002 37
Uncore Performance Monitoring
Cacheing Agent (Cbo) Performance Monitoring
2.3.4.2 Acronyms frequently used in CBo Events:
The Rings:
AD (Address) Ring - Core Read/Write Requests and Intel QPI Snoops. Carries Intel QPI requests and
snoop responses from C to QPI.
BL (Block or Data) Ring - Data == 2 transfers for 1 cache line
AK (Acknowledge) Ring - Acknowledges QPI to CBo and CBo to Core. Carries snoop responses from
Core to CBo.
IV (Invalidate) Ring - CBo Snoop requests of core caches
Internal CBo Queues:
IRQ - Ingress Request Queue on AD Ring. Associated with requests from core.
IPQ - Ingress Probe Queue on AD Ring. Associated with snoops from QPI LL.
ISMQ - Ingress Subsequent Messages (response queue). Associated with messages responses to
ingress requests (e.g. data responses, QPI complete messages, core snoop response messages and
GO reset queue).
TOR - Table Of Requests. Tracks pending CBo transactions.
QPI_IGR - QPI credits for AD or BL ring. Credits to access the QPI are necessary to broadcast
snoops.
RxR (aka IGR) /TxR (aka EGR) - Ingress (requests from the Cores) and Egress (requests headed
for the Ring) queues
2.3.4.3 The Queues:
There are several internal occupancy queue counters, each of which is 5bits wide and dedicated to its
queue: IRQ, IPQ, ISMQ, QPI_IGR, IGR, EGR and the TOR.
2.3.5 CBO Box Events Ordered By Code
The following table summarizes the directly measured CBO Box events.
Symbol Name
Event
Code
Ctrs
Max
Inc/
Cyc
Description
CLOCKTICKS 0x00 0-3 1 Uncore Clocks
TxR_INSERTS 0x02 0-1 1 Egress Allocations
TxR_ADS_USED 0x04 0-1 1
RING_BOUNCES 0x05 0-1 1 Number of LLC responses that bounced on
the Ring.
RING_SRC_THRTL 0x07 0-1 1
RxR_OCCUPANCY 0x11 0 20 Ingress Occupancy
RxR_EXT_STARVED 0x12 0-1 1 Ingress Arbiter Blocking Cycles
RxR_INSERTS 0x13 0-1 1 Ingress Allocations
RING_AD_USED 0x1b 2-3 1 AD Ring In Use
RING_AK_USED 0x1c 2-3 1 AK Ring In Use
RING_BL_USED 0x1d 2-3 1 BL Ring in Use
RING_IV_USED 0x1e 2-3 1 IV Ring in Use