Intel 64 and IA-32 Architectures Software Developers Manual Volume 3B, System Programming Guide Part 2

Table Of Contents
Vol. 3 A-191
PERFORMANCE-MONITORING EVENTS
External
Bus Logic
(EBL)
2
62H BUS_DRDY_
CLOCKS
00H
(Self)
20H
(Any)
Number of clocks during
which DRDY# is asserted.
Utilization of the external
system data bus during
data transfers.
Unit Mask = 00H
counts bus clocks
when the processor
is driving DRDY#.
Unit Mask = 20H
counts in processor
clocks when any
agent is driving
DRDY#.
63H BUS_LOCK_
CLOCKS
00H
(Self)
20H
(Any)
Number of clocks during
which LOCK# is asserted
on the external system
bus.
3
Always counts in
processor clocks.
60H BUS_REQ_
OUTSTANDING
00H
(Self)
Number of bus requests
outstanding.
This counter is
incremented by the
number of cacheable
read bus requests
outstanding in any given
cycle.
Counts only DCU
full-line cacheable
reads, not RFOs,
writes, instruction
fetches, or anything
else. Counts
“waiting for bus to
complete” (last data
chunk received).
65H BUS_TRAN_BRD 00H
(Self)
20H
(Any)
Number of burst read
transactions.
66H BUS_TRAN_RFO 00H
(Self)
20H
(Any)
Number of completed
read for ownership
transactions.
67H BUS_TRANS_WB 00H
(Self)
20H
(Any)
Number of completed
write back transactions.
Table A-18. Events That Can Be Counted with the P6 Family Performance-
Monitoring Counters (Contd.)
Unit
Event
Num.
Mnemonic Event
Name
Unit
Mask Description Comments