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Jiri Olsa 0ce2da1483 perf stat: Display user and system time
Adding the support to read rusage data once the workload is finished and
display the system/user time values:

  $ perf stat --null perf bench sched pipe
  ...

   Performance counter stats for 'perf bench sched pipe':

       5.342599256 seconds time elapsed

       2.544434000 seconds user
       4.549691000 seconds sys

It works only in non -r mode and only for workload target.

So as of now, for workload targets, we display 3 types of timings. The
time we meassure in perf stat from enable to disable+period:

       5.342599256 seconds time elapsed

The time spent in user and system lands, displayed only for workload
session/target:

       2.544434000 seconds user
       4.549691000 seconds sys

Those times are the very same displayed by 'time' tool.  They are
returned by wait4 call via the getrusage struct interface.

Committer notes:

Had to rename some variables to avoid this on older systems such as
centos:6:

  builtin-stat.c: In function 'print_footer':
  builtin-stat.c:1831: warning: declaration of 'stime' shadows a global declaration
  /usr/include/time.h:297: warning: shadowed declaration is here

Committer testing:

  # perf stat --null time perf bench sched pipe
  # Running 'sched/pipe' benchmark:
  # Executed 1000000 pipe operations between two processes

       Total time: 5.526 [sec]

         5.526534 usecs/op
           180945 ops/sec
  1.00user 6.25system 0:05.52elapsed 131%CPU (0avgtext+0avgdata 8056maxresident)k
  0inputs+0outputs (0major+606minor)pagefaults 0swaps

   Performance counter stats for 'time perf bench sched pipe':

         5.530978744 seconds time elapsed

         1.004037000 seconds user
         6.259937000 seconds sys

  #

Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180605121313.31337-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-06-06 12:52:04 -03:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-06-02 17:35:53 -07:00
LICENSES LICENSES: Add MPL-1.1 license 2018-01-06 10:59:44 -07:00
arch Merge remote-tracking branch 'tip/perf/urgent' into perf/core 2018-06-04 10:28:20 -03:00
block blk-mq: fix sysfs inflight counter 2018-04-26 09:02:01 -06:00
certs certs/blacklist_nohashes.c: fix const confusion in certs blacklist 2018-02-21 15:35:43 -08:00
crypto crypto: drbg - set freed buffers to NULL 2018-04-21 00:57:00 +08:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-06-02 17:35:53 -07:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs Merge candidates for 4.17-rc 2018-06-02 09:55:44 -07:00
include Merge remote-tracking branch 'tip/perf/urgent' into perf/core 2018-06-04 10:28:20 -03:00
init init/main.c: include <linux/mem_encrypt.h> 2018-05-25 18:12:11 -07:00
ipc ipc/shm: fix shmat() nil address after round-down when remapping 2018-05-25 18:12:11 -07:00
kernel Merge remote-tracking branch 'tip/perf/urgent' into perf/core 2018-06-04 10:28:20 -03:00
lib idr: fix invalid ptr dereference on item delete 2018-05-25 18:12:10 -07:00
mm mm: fix the NULL mapping case in __isolate_lru_page() 2018-06-02 09:33:47 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2018-06-02 17:35:53 -07:00
samples x86/cpufeature: Guard asm_volatile_goto usage for BPF compilation 2018-05-13 21:49:14 +02:00
scripts checkpatch: fix macro argument precedence test 2018-05-25 18:12:11 -07:00
security selinux/stable-4.17 PR 20180530 2018-05-30 16:35:07 -05:00
sound ALSA: hda - Fix runtime PM 2018-05-24 20:16:47 +02:00
tools perf stat: Display user and system time 2018-06-06 12:52:04 -03:00
usr kbuild: rename built-in.o to built-in.a 2018-03-26 02:01:19 +09:00
virt KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls 2018-05-15 13:36:53 +02:00
.clang-format clang-format: add configuration file 2018-04-11 10:28:35 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap Merge candidates for 4.17 merge window 2018-04-06 17:35:43 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS/CREDITS: Drop METAG ARCHITECTURE 2018-03-05 16:34:24 +00:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2018-06-02 09:52:22 -07:00
Makefile Linux 4.17-rc7 2018-05-27 13:01:47 -07:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -06:00

README

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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.