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perf_event_open.2: 4.1 data_offset and data_size fields 

This manpage patch relates to the addition of the data_offset
and data_size fields to the perf_event mmap buffer, as added
in the following commit:

	commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
	Author: Alexander Shishkin <alexander.shishkin@linux.intel.com>

	perf: Add data_{offset,size} to user_page

	Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
	Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
	Cc: Borislav Petkov <bp@alien8.de>
	Cc: Frederic Weisbecker <fweisbec@gmail.com>
	Cc: H. Peter Anvin <hpa@zytor.com>
	Cc: Kaixu Xia <kaixu.xia@linaro.org>
	Cc: Linus Torvalds <torvalds@linux-foundation.org>
	Cc: Mike Galbraith <efault@gmx.de>
	Cc: Paul Mackerras <paulus@samba.org>
	Cc: Robert Richter <rric@kernel.org>
	Cc: Stephane Eranian <eranian@google.com>
	Cc: Thomas Gleixner <tglx@linutronix.de>
	Cc: acme@infradead.org
	Cc: adrian.hunter@intel.com
	Cc: kan.liang@intel.com
	Cc: markus.t.metzger@intel.com
	Cc: mathieu.poirier@linaro.org
	Link: http://lkml.kernel.org/r/1421237903-181015-2-git-send-email-alexander.shishkin@linux.intel.com
	Signed-off-by: Ingo Molnar <mingo@kernel.org>

Signed-off-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
This commit is contained in:
Vince Weaver 2015-07-23 13:11:10 -04:00 committed by Michael Kerrisk
parent b0f7b411be
commit 21d9849abb
1 changed files with 13 additions and 0 deletions
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13
man2/perf_event_open.2
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@ -1414,6 +1414,9 @@ struct perf_event_mmap_page {
__u64 __reserved[120]; /* Pad to 1k */
__u64 data_head; /* head in the data section */
__u64 data_tail; /* user-space written tail */
__u64 data_offset; /* where the buffer starts */
__u64 data_size; /* data buffer size */
}
.fi
.in
@ -1630,6 +1633,16 @@ the
.I data_tail
value should be written by user space to reflect the last read data.
In this case, the kernel will not overwrite unread data.
.TP
.IR data_offset " (since Linux 4.1)"
.\" commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
Contains the offset of the location in the mmap buffer
where perf sample data begins.
.TP
.IR data_size " (since Linux 4.1)"
.\" commit e8c6deac69629c0cb97c3d3272f8631ef17f8f0f
Contains the size of the perf sample region within
the mmap buffer.
.PP
The following 2^n ring-buffer pages have the layout described below.