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authorMark Brown <broonie@opensource.wolfsonmicro.com>2010-01-25 09:52:48 -0500
committerMark Brown <broonie@opensource.wolfsonmicro.com>2010-01-25 09:52:48 -0500
commitf1487fcbe47cd2bc0c71e8598bf9eb6a82dec544 (patch)
tree4c7abed6047538c13dd024a8ecffd15f31b4609a /tools/perf/design.txt
parent84549d239ab9bb2e3a85c6efcf0e6478a38b4260 (diff)
parent40aa7030e5213a43e9e0554fd7f95534ea310bf3 (diff)
Merge branch 'for-2.6.33' into for-2.6.34
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.