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authorIngo Molnar <mingo@elte.hu>2010-02-08 02:55:43 -0500
committerIngo Molnar <mingo@elte.hu>2010-02-08 02:55:46 -0500
commit6d3e0907b8b239d16720d144e2675ecf10d3bc3b (patch)
treee0b0743b5f6f82b057cafc4f3687396a6e01a0b4 /tools/perf/design.txt
parent23577256953c870de9b724c3a2611ce7be6a1e4e (diff)
parent50200df462023b187d80a99a52f5f2cfe3c86c26 (diff)
Merge branch 'sched/urgent' into sched/core
Merge reason: Merge dependent fix, update to latest -rc. Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'tools/perf/design.txt')
-rw-r--r--tools/perf/design.txt8
1 files changed, 4 insertions, 4 deletions
diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index f000c30877ac..8d0de5130db3 100644
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -21,7 +21,7 @@ There's one file descriptor per virtual counter used.
21The special file descriptor is opened via the perf_event_open() 21The special file descriptor is opened via the perf_event_open()
22system call: 22system call:
23 23
24 int sys_perf_event_open(struct perf_event_hw_event *hw_event_uptr, 24 int sys_perf_event_open(struct perf_event_attr *hw_event_uptr,
25 pid_t pid, int cpu, int group_fd, 25 pid_t pid, int cpu, int group_fd,
26 unsigned long flags); 26 unsigned long flags);
27 27
@@ -32,9 +32,9 @@ can be used to set the blocking mode, etc.
32Multiple counters can be kept open at a time, and the counters 32Multiple counters can be kept open at a time, and the counters
33can be poll()ed. 33can be poll()ed.
34 34
35When creating a new counter fd, 'perf_event_hw_event' is: 35When creating a new counter fd, 'perf_event_attr' is:
36 36
37struct perf_event_hw_event { 37struct perf_event_attr {
38 /* 38 /*
39 * The MSB of the config word signifies if the rest contains cpu 39 * The MSB of the config word signifies if the rest contains cpu
40 * specific (raw) counter configuration data, if unset, the next 40 * specific (raw) counter configuration data, if unset, the next
@@ -399,7 +399,7 @@ Notification of new events is possible through poll()/select()/epoll() and
399fcntl() managing signals. 399fcntl() managing signals.
400 400
401Normally a notification is generated for every page filled, however one can 401Normally a notification is generated for every page filled, however one can
402additionally set perf_event_hw_event.wakeup_events to generate one every 402additionally set perf_event_attr.wakeup_events to generate one every
403so many counter overflow events. 403so many counter overflow events.
404 404
405Future work will include a splice() interface to the ring-buffer. 405Future work will include a splice() interface to the ring-buffer.