Setting Events To Monitor - Red Hat ENTERPRISE LINUX 5 - DEPLOYMENT Deployment Manual

Note
Even if OProfile is configured not to profile the kernel, the SMP kernel still must be running
so that the oprofile module can be loaded from it.
Setting whether samples should be collected within the kernel only changes what data is collected,
not how or where the collected data is stored. To generate different sample files for the kernel and
application libraries, refer to

39.2.2. Setting Events to Monitor

Most processors contain counters, which are used by OProfile to monitor specific events. As shown
Table 39.2, "OProfile Processors and
in
processor.
Processor
Pentium Pro
Pentium II
Pentium III
Pentium 4 (non-hyper-threaded)
Pentium 4 (hyper-threaded)
Athlon
AMD64
Itanium
Itanium 2
TIMER_INT
IBM eServer iSeries and pSeries
IBM eServer S/390 and S/390x
IBM eServer zSeries
Table 39.2. OProfile Processors and Counters
Table 39.2, "OProfile Processors and Counters"
Use
detected and to determine the number of events that can be monitored simultaneously. timer is used
as the processor type if the processor does not have supported performance monitoring hardware.
If timer is used, events cannot be set for any processor because the hardware does not have
support for hardware performance counters. Instead, the timer interrupt is used for profiling.
If timer is not used as the processor type, the events monitored can be changed, and counter 0
for the processor is set to a time-based event by default. If more than one counter exists on the
processor, the counters other than counter 0 are not set to an event by default. The default events
monitored are shown in
Section 39.2.3, "Separating Kernel and User-space
Counters", the number of counters available depends on the
cpu_type
i386/ppro
i386/pii
i386/piii
i386/p4
i386/p4-ht
i386/athlon
x86-64/hammer
ia64/itanium
ia64/itanium2
timer
timer
ppc64/power4
ppc64/power5
ppc64/970
timer
timer
Table 39.3, "Default Events".
to verify that the correct processor type was
Setting Events to Monitor
Profiles".
Number of Counters
2
2
2
8
4
4
4
4
4
1
1
8
6
8
1
1
537