LDP
/
man-pages
mirror of https://github.com/mkerrisk/man-pages
0
1
Fork 0
Code Releases Activity

perf_event_open.2: Linux 3.12 adds PERF_SAMPLE_IDENTIFIER 

A new PERF_SAMPLE_IDENTIFIER sample type was added in Linux 3.12.

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 2013-11-06 13:30:41 -05:00 committed by Michael Kerrisk
parent dab3845542
commit 7480dabbeb
1 changed files with 61 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

62
man2/perf_event_open.2
View File

@ -687,6 +687,27 @@ Records the data source: where in the memory hierarchy
the data associated with the sampled instruction came from.
This is only available if the underlying hardware
supports this feature.
.TP
.BR PERF_SAMPLE_IDENTIFIER " (Since Linux 3.12)"
Places the SAMPLE_ID value in a fixed position in the record,
either at the beginning (for sample events) or at the end
(if a non-sample event).
This was necessary because a sample stream may have
records from various different event sources with different
.I sample_type
settings.
Parsing the event stream properly was not possible because the
format of the record was needed to find SAMPLE_ID, but
the the format could not be found without knowing what
event the sample belonged to (causing a circular
dependency).
This new
.B PERF_SAMPLE_IDENTIFIER
setting makes the event stream always parsable
by putting SAMPLE_ID in a fixed location, even though
it means having duplicate SAMPLE_ID values in records.
.RE
.TP
.IR "read_format"
@ -867,12 +888,33 @@ field, but enables including data mmap events
in the ring-buffer.
.TP
.IR "sample_id_all" " (Since Linux 2.6.38)"
If set, then TID, TIME, ID, CPU, and STREAM_ID can
If set, then TID, TIME, ID, STREAM_ID, and CPU can
additionally be included in
.RB non- PERF_RECORD_SAMPLE s
if the corresponding
.I sample_type
is selected.
If
.B PERF_SAMPLE_IDENTIFIER
is specified than an additional ID value is included
as the last value to ease parsing the record stream.
This may lead to the
.I id
value appearing twice.
The layout is described by this pseudo-structure:
.in +4n
.nf
struct sample_id {
{ u32 pid, tid; } /* if PERF_SAMPLE_TID set */
{ u64 time; } /* if PERF_SAMPLE_TIME set */
{ u64 id; } /* if PERF_SAMPLE_ID set */
{ u64 stream_id;} /* if PERF_SAMPLE_STREAM_ID set */
{ u32 cpu, res; } /* if PERF_SAMPLE_CPU set */
{ u64 id; } /* if PERF_SAMPLE_IDENTIFIER set */
};
.fi
.TP
.IR "exclude_host" " (Since Linux 3.2)"
Do not measure time spent in VM host.
@ -1392,6 +1434,7 @@ The values in the corresponding record (that follows the header)
depend on the
.I type
selected as shown.
.RS
.TP 4
.B PERF_RECORD_MMAP
@ -1423,6 +1466,7 @@ struct {
struct perf_event_header header;
u64 id;
u64 lost;
struct sample_id sample_id;
};
.fi
.in
@ -1444,6 +1488,7 @@ struct {
struct perf_event_header header;
u32 pid, tid;
char comm[];
struct sample_id sample_id;
};
.fi
.in
@ -1458,6 +1503,7 @@ struct {
u32 pid, ppid;
u32 tid, ptid;
u64 time;
struct sample_id sample_id;
};
.fi
.in
@ -1472,6 +1518,7 @@ struct {
u64 time;
u64 id;
u64 stream_id;
struct sample_id sample_id;
};
.fi
.in
@ -1486,6 +1533,7 @@ struct {
u32 pid, ppid;
u32 tid, ptid;
u64 time;
struct sample_id sample_id;
};
.fi
.in
@ -1499,6 +1547,7 @@ struct {
struct perf_event_header header;
u32 pid, tid;
struct read_format values;
struct sample_id sample_id;
};
.fi
.in
@ -1510,6 +1559,7 @@ This record indicates a sample.
.nf
struct {
struct perf_event_header header;
u64 sample_id; /* if PERF_SAMPLE_IDENTIFIER */
u64 ip; /* if PERF_SAMPLE_IP */
u32 pid, tid; /* if PERF_SAMPLE_TID */
u64 time; /* if PERF_SAMPLE_TIME */
@ -1538,6 +1588,16 @@ struct {
.fi
.RS 4
.TP 4
.I sample_id
If
.B PERF_SAMPLE_IDENTIFIER
is enabled, a 64-bit unique ID is included.
This is a duplication of the
.B PERF_SAMPLE_ID
.I id
value, but included at the beginning of the sample
so parsers can easily obtain the value.
.TP
.I ip
If
.B PERF_SAMPLE_IP