[PATCH 05/16] perf Documentation: add event parameters
Cody P Schafer
dev at codyps.com
Wed May 28 10:22:00 EST 2014
Event parameters are a basic way for partial events to be specified in
sysfs with per-event names given to the fields that need to be filled in
when using a particular event.
It is intended for supporting cases where the single 'cpu' parameter is
insufficient. For example, POWER 8 has events for physical
sockets/cores/cpus that are accessible from with virtual machines. To
keep using the single 'cpu' parameter we'd need to perform a mapping
between Linux's cpus and the physical machine's cpus (in this case
Linux is running under a hypervisor). This isn't possible because
bindings between our cpus and physical cpus may not be fixed, and we
probably won't have a "cpu" on each physical cpu.
CC: Sukadev Bhattiprolu <sukadev at linux.vnet.ibm.com>
Signed-off-by: Cody P Schafer <dev at codyps.com>
Documentation/ABI/testing/sysfs-bus-event_source-devices-events | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-bus-event_source-devices-events b/Documentation/ABI/testing/sysfs-bus-event_source-devices-events
index 20979f8..c1f9850 100644
@@ -52,12 +52,18 @@ Description: Per-pmu performance monitoring events specific to the running syste
Each of the assignments indicates a value to be assigned to a
particular set of bits (as defined by the format file
corresponding to the <term>) in the perf_event structure passed
to the perf_open syscall.
+ In the case of the last example, a value replacing "phys_cpu"
+ would need to be provided by the user selecting the particular
+ event. This is refered to as "event parameterization". All
+ non-numerical values indicate an event parameter.
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