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| author |   Alexis Berlemont <alexis.berlemont@gmail.com> | 2016-10-10 07:43:28 +0200 |
|---|---|---|
| committer |   Arnaldo Carvalho de Melo <acme@redhat.com> | 2016-10-24 11:07:43 -0300 |
| commit | e36b7821a985325dd7074de96deface5c9c6d700 (patch) | |
| tree | 59dc7200af2f06380cd7bcba99fd9a4d474a4bea /tools/perf/Documentation/perf-trace.txt | |
| parent | perf hists browser: Dynamically change verbosity level (diff) | |
| download | linux-dev-e36b7821a985325dd7074de96deface5c9c6d700.tar.xz linux-dev-e36b7821a985325dd7074de96deface5c9c6d700.zip | |
perf trace: Implement --delay
In the perf wiki todo-list[1], there is an entry regarding initial-delay
and 'perf trace'; the following small patch tries to fulfill this point.
It has been generated against the branch tip/perf/core.
It has only been implemented in the "trace__run" case.
Ex.:
$ sudo strace -- ./perf trace --delay 5 sleep 1 2>&1
...
fcntl(7, F_SETFL, O_RDONLY|O_NONBLOCK) = 0
ioctl(7, PERF_EVENT_IOC_ID, 0x7ffc8fd35718) = 0
ioctl(11, PERF_EVENT_IOC_SET_OUTPUT, 0x7) = 0
fcntl(11, F_SETFL, O_RDONLY|O_NONBLOCK) = 0
ioctl(11, PERF_EVENT_IOC_ID, 0x7ffc8fd35718) = 0
write(6, "\0", 1) = 1
close(6) = 0
nanosleep({0, 5000000}, NULL) = 0 # DELAY OF 5 MS BEFORE ENABLING THE EVENTS
ioctl(3, PERF_EVENT_IOC_ENABLE, 0) = 0
ioctl(4, PERF_EVENT_IOC_ENABLE, 0) = 0
ioctl(5, PERF_EVENT_IOC_ENABLE, 0) = 0
ioctl(7, PERF_EVENT_IOC_ENABLE, 0) = 0
...
[1]: https://perf.wiki.kernel.org/index.php/Todo
Signed-off-by: Alexis Berlemont <alexis.berlemont@gmail.com>
Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20161010054328.4028-2-alexis.berlemont@gmail.com
[ Add entry to the manpage, cut'n'pasted from stat's and record's ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/Documentation/perf-trace.txt')
| -rw-r--r-- | tools/perf/Documentation/perf-trace.txt | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/perf/Documentation/perf-trace.txt b/tools/perf/Documentation/perf-trace.txt index 1ab0782369b1..781b019751a4 100644 --- a/tools/perf/Documentation/perf-trace.txt +++ b/tools/perf/Documentation/perf-trace.txt @@ -39,6 +39,11 @@ OPTIONS Prefixing with ! shows all syscalls but the ones specified. You may need to escape it. +-D msecs:: +--delay msecs:: +After starting the program, wait msecs before measuring. This is useful to +filter out the startup phase of the program, which is often very different. + -o:: --output=:: Output file name. |