From dab3845542bd8e1aefa8b956949c0a5875ad93db Mon Sep 17 00:00:00 2001 From: Vince Weaver Date: Wed, 6 Nov 2013 13:28:50 -0500 Subject: [PATCH] perf_event_open.2: PERF_COUNT_SW_DUMMY support Support for the PERF_COUNT_SW_DUMMY event type was added in Linux 3.12. Signed-off-by: Vince Weaver Signed-off-by: Michael Kerrisk --- man2/perf_event_open.2 | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/man2/perf_event_open.2 b/man2/perf_event_open.2 index 4ff96909b..14f5d3c83 100644 --- a/man2/perf_event_open.2 +++ b/man2/perf_event_open.2 @@ -468,6 +468,13 @@ This counts the number of emulation faults. The kernel sometimes traps on unimplemented instructions and emulates them for user space. This can negatively impact performance. +.TP +.BR PERF_COUNT_SW_DUMMY " (Since Linux 3.12)" +This is a placeholder event that counts nothing. +Informational sample record types such as mmap or comm +must be associated with an active event. +This dummy event allows gathering such records without requiring +a counting event. .RE .RS