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perf_counter: frequency based adaptive irq_period

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Instead of specifying the irq_period for a counter, provide a target interrupt
frequency and dynamically adapt the irq_period to match this frequency.

[ Impact: new perf-counter attribute/feature ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
LKML-Reference: <20090515132018.646195868@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-05-15 15:19:28 +02:00 • committed by Ingo Molnar
commit 60db5e09c1
4 changed files with 68 additions and 27 deletions
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10
include/linux/perf_counter.h
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@ -130,7 +130,11 @@ struct perf_counter_hw_event {
*/
__u64 config;
__u64 irq_period;
union {
__u64 irq_period;
__u64 irq_freq;
};
__u32 record_type;
__u32 read_format;
@ -146,8 +150,9 @@ struct perf_counter_hw_event {
mmap : 1, /* include mmap data */
munmap : 1, /* include munmap data */
comm : 1, /* include comm data */
freq : 1, /* use freq, not period */
__reserved_1 : 52;
__reserved_1 : 51;
__u32 extra_config_len;
__u32 wakeup_events; /* wakeup every n events */
@ -337,6 +342,7 @@ struct hw_perf_counter {
atomic64_t prev_count;
u64 irq_period;
atomic64_t period_left;
u64 interrupts;
#endif
};