Vol. 3B 18-81

PERFORMANCE MONITORING

18.14 INTEL

®

 XEON PHI

â„¢

 PROCESSOR 7200/5200/3200 PERFORMANCE 

MONITORING 

The Intel

®

 Xeon Phiâ„¢ processor 7200/5200/3200 series are based on the Knights Landing microarchitecture. The 

performance monitoring capabilities are distributed between its tiles (pair of processor cores) and untile 
(connecting many tiles in a physical processor package). Functional details of the tiles and untile of the Knights 
Landing microarchitecture can be found in Chapter 16 of Intel® 64 and IA-32 Architectures Optimization Reference 
Manual.
The PMU inside a processor core supports architectural performance monitoring capability with version ID 3. 
A complete description of the tile and untile PMU programming interfaces for Intel Xeon Phi processors based on 
the Knights Landing microarchitecture can be found in the Technical Document section at 
http://www.intel.com/content/www/us/en/processors/xeon/xeon-phi-detail.html.
Performance monitoring events supported by the tile and untile PMU can be found at 
http://www.intel.com/content/www/us/en/processors/xeon/xeon-phi-detail.html and at https://down-
load.01.org/perfmon/.

Table 18-62.  MSR_OFFCORE_RSP_x Snoop Info Field Definition (CPUID Signature 06_4EH, 06_5EH)

Subtype

Bit Name

Offset

Description

Snoop Info

SNOOP_NONE

31

(R/W). No details on snoop-related information

SNOOP_NOT_NEEDED

32

(R/W). No snoop was needed to satisfy the request.

SNOOP_MISS

33

(R/W). A snoop was needed and it missed all snooped caches:
-For LLC Hit, ReslHitl was returned by all cores
-For LLC Miss, Rspl was returned by all sockets and data was returned 

from DRAM.

SNOOP_HIT_NO_FWD

34

(R/W). A snoop was needed and it hits in at least one snooped cache. 

Hit denotes a cache-line was valid before snoop effect. This includes:
-Snoop Hit w/ Invalidation (LLC Hit, RFO)
-Snoop Hit, Left Shared (LLC Hit/Miss, IFetch/Data_RD)
-Snoop Hit w/ Invalidation and No Forward (LLC Miss, RFO Hit S)
In the LLC Miss case, data is returned from DRAM.

SNOOP_HIT_WITH_FWD

35

(R/W). A snoop was needed and data was forwarded from a remote 

socket. This includes:
-Snoop Forward Clean, Left Shared (LLC Hit/Miss, 

IFetch/Data_RD/RFT).

SNOOP_HITM

36

(R/W). A snoop was needed and it HitM-ed in local or remote cache. 

HitM denotes a cache-line was in modified state before effect as a 

results of snoop. This includes:
-Snoop HitM w/ WB (LLC miss, IFetch/Data_RD)
-Snoop Forward Modified w/ Invalidation (LLC Hit/Miss, RFO)
-Snoop MtoS (LLC Hit, IFetch/Data_RD).

SNOOP_NON_DRAM

37

(R/W). Target was non-DRAM system address. This includes MMIO 

transactions.