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| author |   Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-05-05 17:50:26 +0200 |
|---|---|---|
| committer |   Ingo Molnar <mingo@elte.hu> | 2009-05-05 20:18:33 +0200 |
| commit | 2023b359214bbc5bad31571cf50d7fb83b535c0a (patch) | |
| tree | 991ca078cd79b883cd09da2b349055e136e13a0c /kernel/perf_counter.c | |
| parent | perf_counter: fix the output lock (diff) | |
| download | linux-dev-2023b359214bbc5bad31571cf50d7fb83b535c0a.tar.xz linux-dev-2023b359214bbc5bad31571cf50d7fb83b535c0a.zip | |
perf_counter: inheritable sample counters
Redirect the output to the parent counter and put in some sanity checks.
[ Impact: new perfcounter feature - inherited sampling counters ]
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <20090505155437.331556171@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_counter.c')
| -rw-r--r-- | kernel/perf_counter.c | 32 |
1 files changed, 30 insertions, 2 deletions
diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c index c881afef997b..60e55f0b48f4 100644 --- a/kernel/perf_counter.c +++ b/kernel/perf_counter.c @@ -738,10 +738,18 @@ static void perf_counter_enable(struct perf_counter *counter) spin_unlock_irq(&ctx->lock); } -static void perf_counter_refresh(struct perf_counter *counter, int refresh) +static int perf_counter_refresh(struct perf_counter *counter, int refresh) { + /* + * not supported on inherited counters + */ + if (counter->hw_event.inherit) + return -EINVAL; + atomic_add(refresh, &counter->event_limit); perf_counter_enable(counter); + + return 0; } /* @@ -1307,7 +1315,7 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg) perf_counter_disable_family(counter); break; case PERF_COUNTER_IOC_REFRESH: - perf_counter_refresh(counter, arg); + err = perf_counter_refresh(counter, arg); break; case PERF_COUNTER_IOC_RESET: perf_counter_reset(counter); @@ -1814,6 +1822,12 @@ static int perf_output_begin(struct perf_output_handle *handle, struct perf_mmap_data *data; unsigned int offset, head; + /* + * For inherited counters we send all the output towards the parent. + */ + if (counter->parent) + counter = counter->parent; + rcu_read_lock(); data = rcu_dereference(counter->data); if (!data) @@ -1995,6 +2009,9 @@ static void perf_counter_output(struct perf_counter *counter, if (record_type & PERF_RECORD_ADDR) perf_output_put(&handle, addr); + /* + * XXX PERF_RECORD_GROUP vs inherited counters seems difficult. + */ if (record_type & PERF_RECORD_GROUP) { struct perf_counter *leader, *sub; u64 nr = counter->nr_siblings; @@ -2281,6 +2298,11 @@ int perf_counter_overflow(struct perf_counter *counter, int events = atomic_read(&counter->event_limit); int ret = 0; + /* + * XXX event_limit might not quite work as expected on inherited + * counters + */ + counter->pending_kill = POLL_IN; if (events && atomic_dec_and_test(&counter->event_limit)) { ret = 1; @@ -2801,6 +2823,12 @@ perf_counter_alloc(struct perf_counter_hw_event *hw_event, pmu = NULL; + /* + * we currently do not support PERF_RECORD_GROUP on inherited counters + */ + if (hw_event->inherit && (hw_event->record_type & PERF_RECORD_GROUP)) + goto done; + if (perf_event_raw(hw_event)) { pmu = hw_perf_counter_init(counter); goto done; |