[patch] perf_event_open.2: Exclude_hv clarification

From: Vince Weaver
Date: Wed Feb 11 2015 - 14:01:45 EST

This manpage patch relates to the exclude_hv bit added to the kernel
in the following commit:

exclude_hv; Linux 2.6.31
commit 0475f9ea8e2cc030298908949e0d5da9f2fc2cfe
Author: Paul Mackerras <paulus@xxxxxxxxx>

perf_counters: allow users to count user, kernel and/or hypervisor events

Signed-off-by: Paul Mackerras <paulus@xxxxxxxxx>

The updated manpage text points out that the exclude_hv
"exclude hypervisor" bit only applies on hardware that
supports this feature (such as PowerPC)
and is silently ignored on other platforms such as x86.

This is a resend of the patch; the previous time I sent it
(http://thread.gmane.org/gmane.linux.man/7500) it did not
receive any comments.

Signed-off-by: Vince Weaver <vincent.weaver@xxxxxxxxx>

diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2
index 39c8d8c..665aa31 100644
--- a/man2/perf_event_open.2
+++ b/man2/perf_event_open.2
@@ -856,10 +856,9 @@ If this bit is set, the count excludes events that happen in kernel-space.
.IR "exclude_hv"
If this bit is set, the count excludes events that happen in the
-This is mainly for PMUs that have built-in support for handling this
-(such as POWER).
-Extra support is needed for handling hypervisor measurements on most
+This is mainly for PMUs that have built-in hardware support
+for this feature (such as POWER; this setting is silently
+ignored on x86).
.IR "exclude_idle"
If set, don't count when the CPU is idle.
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