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c30d630d1b
Allow user to limit output to one or more CPUs. Really helpful on
systems with a large number of cpus.
Committer testing:
# perf sched record -a sleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 1.765 MB perf.data (1412 samples) ]
[root@quaco ~]# perf sched timehist | head
Samples do not have callchains.
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
--------------- ------ ------------------------------ --------- --------- ---------
66307.802686 [0000] perf[13086] 0.000 0.000 0.000
66307.802700 [0000] migration/0[12] 0.000 0.001 0.014
66307.802766 [0001] perf[13086] 0.000 0.000 0.000
66307.802774 [0001] migration/1[15] 0.000 0.001 0.007
66307.802841 [0002] perf[13086] 0.000 0.000 0.000
66307.802849 [0002] migration/2[20] 0.000 0.001 0.008
66307.802913 [0003] perf[13086] 0.000 0.000 0.000
#
# perf sched timehist --cpu 2 | head
Samples do not have callchains.
time cpu task name wait time sch delay run time
[tid/pid] (msec) (msec) (msec)
--------------- ------ ------------------------------ --------- --------- ---------
66307.802841 [0002] perf[13086] 0.000 0.000 0.000
66307.802849 [0002] migration/2[20] 0.000 0.001 0.008
66307.964485 [0002] <idle> 0.000 0.000 161.635
66307.964811 [0002] CPU 0/KVM[3589/3561] 0.000 0.056 0.325
66307.965477 [0002] <idle> 0.325 0.000 0.666
66307.965553 [0002] CPU 0/KVM[3589/3561] 0.666 0.024 0.076
66307.966456 [0002] <idle> 0.076 0.000 0.903
#
Signed-off-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lore.kernel.org/lkml/20191204173925.66976-1-dsahern@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.