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author | Andi Kleen <ak@linux.intel.com> | 2016-03-03 15:57:36 -0800 |
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committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-03-10 16:49:40 -0300 |
commit | 54b5091606c18f68a7fc8b4ab03ac4592c7d2922 (patch) | |
tree | a6bb0f667c144e5b77efc72244f6ff93c6716283 /tools/perf/Documentation | |
parent | 6b45f7b2a37b0e00693985fd0abfc8e0319f91ce (diff) | |
download | linux-54b5091606c18f68a7fc8b4ab03ac4592c7d2922.tar.bz2 |
perf stat: Implement --metric-only mode
Add a new mode to only print metrics. Sometimes we don't care about the
raw values, just want the computed metrics. This allows more compact
printing, so with -I each sample is only a single line. This also
allows easier plotting and processing with other tools.
The main target is with using --topdown, but it also works with -T and
standard perf stat. A few metrics are not supported.
To avoiding having to hardcode all the metrics in the code it uses a two
pass approach: first compute dummy metrics and only print the headers in
the print_metric callback. Then use the callback to print the actual
values.
There are some additional changes in the stat printout code to handle
all metrics being on a single line.
One issue is that the column code doesn't know in advance what events
are not supported by the CPU, and it would be hard to find out as this
could change based on dynamic conditions. That causes empty columns in
some cases.
The output can be fairly wide, often you may need more than 80 columns.
Example:
% perf stat -a -I 1000 --metric-only
1.001452803 frontend cycles idle insn per cycle stalled cycles per insn branch-misses of all branches
1.001452803 158.91% 0.66 2.39 2.92%
2.002192321 180.63% 0.76 2.08 2.96%
3.003088282 150.59% 0.62 2.57 2.84%
4.004369835 196.20% 0.98 1.62 3.79%
5.005227314 231.98% 0.84 1.90 4.71%
v2: Lots of updates.
v3: Use slightly narrower columns
v4: Add comment
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: http://lkml.kernel.org/r/1457049458-28956-6-git-send-email-andi@firstfloor.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r-- | tools/perf/Documentation/perf-stat.txt | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-stat.txt b/tools/perf/Documentation/perf-stat.txt index 8812d7319edb..82f0951754dd 100644 --- a/tools/perf/Documentation/perf-stat.txt +++ b/tools/perf/Documentation/perf-stat.txt @@ -147,6 +147,10 @@ Print count deltas every N milliseconds (minimum: 10ms) The overhead percentage could be high in some cases, for instance with small, sub 100ms intervals. Use with caution. example: 'perf stat -I 1000 -e cycles -a sleep 5' +--metric-only:: +Only print computed metrics. Print them in a single line. +Don't show any raw values. Not supported with -A or --per-thread. + --per-socket:: Aggregate counts per processor socket for system-wide mode measurements. This is a useful mode to detect imbalance between sockets. To enable this mode, |