Merge branches 'acpi_pad', 'acpica', 'apei-bugzilla-43282', 'battery', 'cpuidle-coupl...

[GitHub/mt8127/android_kernel_alcatel_ttab.git] / tools / perf / design.txt

diff --git a/tools/perf/design.txt b/tools/perf/design.txt
index bd0bb1b1279b8ec258cc40a231fc4a9d289abd96..67e5d0cace85aad7c70c7ba3ac8bbcf95c4d6e10 100644 (file)
--- a/tools/perf/design.txt
+++ b/tools/perf/design.txt
@@ -409,14 +409,15 @@ Counters can be enabled and disabled in two ways: via ioctl and via
 prctl.  When a counter is disabled, it doesn't count or generate
 events but does continue to exist and maintain its count value.
 
-An individual counter or counter group can be enabled with
+An individual counter can be enabled with
 
-       ioctl(fd, PERF_EVENT_IOC_ENABLE);
+       ioctl(fd, PERF_EVENT_IOC_ENABLE, 0);
 
 or disabled with
 
-       ioctl(fd, PERF_EVENT_IOC_DISABLE);
+       ioctl(fd, PERF_EVENT_IOC_DISABLE, 0);
 
+For a counter group, pass PERF_IOC_FLAG_GROUP as the third argument.
 Enabling or disabling the leader of a group enables or disables the
 whole group; that is, while the group leader is disabled, none of the
 counters in the group will count.  Enabling or disabling a member of a