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| author | Ingo Molnar <mingo@elte.hu> | 2008-12-11 14:03:20 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-12-11 15:45:54 +0100 |
| commit | bae43c9945ebeef15e7952e317efb02393d3bfc7 (patch) | |
| tree | 78d12a494fa9c3f73e76e8d7895ceb94d48d517d | |
| parent | 01b2838c4298c5e0d30b4993c195ac34dd9df61e (diff) | |
| download | kernel_samsung_smdk4412-bae43c9945ebeef15e7952e317efb02393d3bfc7.zip kernel_samsung_smdk4412-bae43c9945ebeef15e7952e317efb02393d3bfc7.tar.gz kernel_samsung_smdk4412-bae43c9945ebeef15e7952e317efb02393d3bfc7.tar.bz2 | |
perf counters: implement PERF_COUNT_TASK_CLOCK
Impact: add new perf-counter type
The 'task clock' counter counts the amount of time a task is executing,
in nanoseconds. It stops ticking when a task is scheduled out either due
to it blocking, sleeping or it being preempted.
This counter type is a Linux kernel based abstraction, it is available
even if the hardware does not support native hardware performance counters.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/perf_counter.h | 7 | ||||
| -rw-r--r-- | kernel/perf_counter.c | 22 |
2 files changed, 27 insertions, 2 deletions
diff --git a/include/linux/perf_counter.h b/include/linux/perf_counter.h index 68f6e3a..30c0ec8 100644 --- a/include/linux/perf_counter.h +++ b/include/linux/perf_counter.h @@ -50,8 +50,11 @@ enum hw_event_types { */ PERF_COUNT_CPU_CLOCK = -1, PERF_COUNT_TASK_CLOCK = -2, - PERF_COUNT_PAGE_FAULTS = -3, - PERF_COUNT_CONTEXT_SWITCHES = -4, + /* + * Future software events: + */ + /* PERF_COUNT_PAGE_FAULTS = -3, + PERF_COUNT_CONTEXT_SWITCHES = -4, */ }; /* diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index 0e93fea..a0fe847 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -855,6 +855,25 @@ static const struct hw_perf_counter_ops perf_ops_cpu_clock = { .hw_perf_counter_read = cpu_clock_perf_counter_read, }; +static void task_clock_perf_counter_enable(struct perf_counter *counter) +{ +} + +static void task_clock_perf_counter_disable(struct perf_counter *counter) +{ +} + +static void task_clock_perf_counter_read(struct perf_counter *counter) +{ + atomic64_counter_set(counter, current->se.sum_exec_runtime); +} + +static const struct hw_perf_counter_ops perf_ops_task_clock = { + .hw_perf_counter_enable = task_clock_perf_counter_enable, + .hw_perf_counter_disable = task_clock_perf_counter_disable, + .hw_perf_counter_read = task_clock_perf_counter_read, +}; + static const struct hw_perf_counter_ops * sw_perf_counter_init(struct perf_counter *counter) { @@ -864,6 +883,9 @@ sw_perf_counter_init(struct perf_counter *counter) case PERF_COUNT_CPU_CLOCK: hw_ops = &perf_ops_cpu_clock; break; + case PERF_COUNT_TASK_CLOCK: + hw_ops = &perf_ops_task_clock; + break; default: break; } |