linux-kernel - [PATCH 0/5] sched/debug: decouple sched_stat tracepoints from CONFIG

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Date:	Fri, 17 Jun 2016 12:43:22 -0500
From:	Josh Poimboeuf <jpoimboe@...hat.com>
To:	Ingo Molnar <mingo@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>
Cc:	linux-kernel@...r.kernel.org,
	Mel Gorman <mgorman@...hsingularity.net>,
	Matt Fleming <matt@...eblueprint.co.uk>,
	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>
Subject: [PATCH 0/5] sched/debug: decouple sched_stat tracepoints from CONFIG_SCHEDSTATS

NOTE: I didn't include any performance numbers because I wasn't able to
get consistent results.  I tried the following on a Xeon E5-2420 v2 CPU:

  $ for i in /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor; do echo -n performance > $i; done
  $ echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo
  $ echo 100 > /sys/devices/system/cpu/intel_pstate/min_perf_pct
  $ echo 0 > /proc/sys/kernel/nmi_watchdog
  $ taskset 0x10 perf stat -n -r10 perf bench sched pipe -l 1000000

I was going to post the numbers from that, both with and without
SCHEDSTATS, but then when I tried to repeat the test on a different day,
the results were surprisingly different, with different conclusions.

So any advice on measuring scheduler performance would be appreciated...

Josh Poimboeuf (5):
  sched/debug: rename and move enqueue_sleeper()
  sched/debug: schedstat macro cleanup
  sched/debug: 'schedstat_val()' -> 'schedstat_val_or_zero()'
  sched/debug: remove several CONFIG_SCHEDSTATS guards
  sched/debug: decouple 'sched_stat_*' tracepoints' from
    CONFIG_SCHEDSTATS

 include/linux/sched.h    |  11 +-
 kernel/latencytop.c      |   2 -
 kernel/profile.c         |   5 -
 kernel/sched/core.c      |  59 ++++------
 kernel/sched/debug.c     | 104 +++++++++--------
 kernel/sched/fair.c      | 290 ++++++++++++++++++++---------------------------
 kernel/sched/idle_task.c |   2 +-
 kernel/sched/stats.h     |  24 ++--
 lib/Kconfig.debug        |   1 -
 9 files changed, 220 insertions(+), 278 deletions(-)

-- 
2.4.11