8fb4b67939
The --all-cgroups option is to enable cgroup profiling support. It
tells kernel to record CGROUP events in the ring buffer so that perf
report can identify task/cgroup association later.
[root@seventh ~]# perf record --all-cgroups --namespaces /wb/cgtest
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.042 MB perf.data (558 samples) ]
[root@seventh ~]# perf report --stdio -s cgroup_id,cgroup,pid
# To display the perf.data header info, please use --header/--header-only options.
#
#
# Total Lost Samples: 0
#
# Samples: 558 of event 'cycles'
# Event count (approx.): 458017341
#
# Overhead cgroup id (dev/inode) Cgroup Pid:Command
# ........ ..................... .......... ...............
#
33.15% 4/0xeffffffb /sub 9615:looper0
32.83% 4/0xf00002f5 /sub/cgrp2 9620:looper2
32.79% 4/0xf00002f4 /sub/cgrp1 9619:looper1
0.35% 4/0xf00002f5 /sub/cgrp2 9618:cgtest
0.34% 4/0xf00002f4 /sub/cgrp1 9617:cgtest
0.32% 4/0xeffffffb / 9615:looper0
0.11% 4/0xeffffffb /sub 9617:cgtest
0.10% 4/0xeffffffb /sub 9618:cgtest
#
# (Tip: Sample related events with: perf record -e '{cycles,instructions}:S')
#
[root@seventh ~]#
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200325124536.2800725-8-namhyung@kernel.org
Link: http://lore.kernel.org/lkml/20200402015249.3800462-1-namhyung@kernel.org
[ Extracted the HAVE_FILE_HANDLE from the followup patch ]
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.