Messages in this thread | | | From | Sukadev Bhattiprolu <> | Subject | [PATCH v5 0/4] Add support for parametrized events | Date | Tue, 2 Dec 2014 18:09:34 -0800 |
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Description of "event parameters" from the documentation patch:
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.
Description of the sysfs contents when events are parameterized (copied from an included patch):
Examples:
domain=0x1,offset=0x8,starting_index=$core
In the case of the last example, a value replacing "$core" 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.
Notes on how perf-list displays parameterized events
PARAMETERIZED EVENTS --------------------
Some pmu events listed by 'perf list' will be displayed with '$xyz' in them. For example:
hv_24x7/HPM_THREAD_NAP_CCYC__PHYS_CORE,starting_index=$core/
This means that when provided as an event, a value for $core must also be supplied. For example:
perf stat -e \ 'hv_24x7/HPM_THREAD_NAP_CCYC__PHYS_CORE,starting_index=2' ...
Changelog[v5] - [Jiri Olsa, Peter Zijlstra] Use '$arg' notation rather than ? to indicate event parameters.
- [Michael Ellerman] Separate the kernel and tool patches in the patchset into different patchsets.
Changelog[v4] - [Jiri Olsa] Rebase to perf/core tree (fix small merge conflict)
Changelog[v3] - [Jiri Olsa] Changed the event parameters are specified. If event file specifes 'param=val' make the usage 'param=123' rather than 'val=123'. (patch 1,2/10) - Shortened event names using "PHYS" and "VCPU" (patch 4/10) - Print help message if invalid parameter is specified or required parameter is missing. - Moved 3 patches that are unrelated to parametrized events into a separate patchset. - Reordered patches so code changes come first.
Changelog[v2] - [Joe Perches, David Laight] Use beNN_to_cpu() instead of guessing the size from type. - Use kmem_cache_free() to free page allocated with kmem_cache_alloc(). - Rebase to recent kernel
Cody P Schafer (4): tools/perf: support parsing parameterized events tools/perf: extend format_alias() to include event parameters perf Documentation: add event parameters tools/perf: Document parameterized and symbolic events
.../testing/sysfs-bus-event_source-devices-events | 6 ++ tools/perf/Documentation/perf-list.txt | 13 +++ tools/perf/Documentation/perf-record.txt | 12 +++ tools/perf/Documentation/perf-stat.txt | 20 ++++- tools/perf/util/parse-events.h | 1 + tools/perf/util/pmu.c | 92 +++++++++++++++++++--- 6 files changed, 128 insertions(+), 16 deletions(-)
-- 1.8.3.1
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