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

Table Of Contents
A-142 Vol. 3
PERFORMANCE-MONITORING EVENTS
2: Currently this event causes
both over and undercounting
by as much as a factor of two
due to an erratum.
3: It is possible for a transaction
that is started as a prefetch to
change the transaction's
internal status, making it no
longer a prefetch. or change
the access result status (hit,
miss) as seen by this event.
IOQ_allocation This event counts the various
types of transactions on the bus.
A count is generated each time a
transaction is allocated into the
IOQ that matches the specified
mask bits. An allocated entry can
be a sector (64 bytes) or a chunks
of 8 bytes.
Requests are counted once per
retry. The event mask bits
constitute 4 bit fields. A
transaction type is specified by
interpreting the values of each bit
field.
Specify one or more event mask
bits in a bit field to select the
value of the bit field.
Each field (bits 0-4 are one field)
are independent of and can be
ORed with the others. The
request type field is further
combined with bit 5 and 6 to form
a binary expression. Bits 7 and 8
form a bit field to specify the
memory type of the target
address.
Table A-9. Performance Monitoring Events Supported by Intel NetBurst
Microarchitecture for Non-Retirement Counting (Contd.)
Event Name Event Parameters Parameter Value Description