linux_dsm_epyc7002/kernel/sched
Rik van Riel 5743021831 sched/cputime: Count actually elapsed irq & softirq time
Currently, if there was any irq or softirq time during 'ticks'
jiffies, the entire period will be accounted as irq or softirq
time.

This is inaccurate if only a subset of the time was actually spent
handling irqs, and could conceivably mis-count all of the ticks during
a period as irq time, when there was some irq and some softirq time.

This can actually happen when irqtime_account_process_tick is called
from account_idle_ticks, which can pass a larger number of ticks down
all at once.

Fix this by changing irqtime_account_hi_update(), irqtime_account_si_update(),
and steal_account_process_ticks() to work with cputime_t time units, and
return the amount of time spent in each mode.

Rename steal_account_process_ticks() to steal_account_process_time(), to
reflect that time is now accounted in cputime_t, instead of ticks.

Additionally, have irqtime_account_process_tick() take into account how
much time was spent in each of steal, irq, and softirq time.

The latter could help improve the accuracy of cputime
accounting when returning from idle on a NO_HZ_IDLE CPU.

Properly accounting how much time was spent in hardirq and
softirq time will also allow the NO_HZ_FULL code to re-use
these same functions for hardirq and softirq accounting.

Signed-off-by: Rik van Riel <riel@redhat.com>
[ Make nsecs_to_cputime64() actually return cputime64_t. ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Radim Krcmar <rkrcmar@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wanpeng Li <wanpeng.li@hotmail.com>
Link: http://lkml.kernel.org/r/1468421405-20056-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-07-14 10:42:34 +02:00
..
auto_group.c sched/core: Move the sched_to_prio[] arrays out of line 2015-12-04 10:34:46 +01:00
auto_group.h sched, timer: Convert usages of ACCESS_ONCE() in the scheduler to READ_ONCE()/WRITE_ONCE() 2015-05-08 12:11:32 +02:00
clock.c sched/clock: Make local_clock()/cpu_clock() inline 2016-04-13 12:25:22 +02:00
completion.c sched/completion: Serialize completion_done() with complete() 2015-02-18 14:27:40 +01:00
core.c sched/core: Panic on scheduling while atomic bugs if kernel.panic_on_warn is set 2016-07-10 20:17:27 +02:00
cpuacct.c sched/cpuacct: Introduce cpuacct.usage_all to show all CPU stats together 2016-07-09 13:56:15 +02:00
cpuacct.h sched/cpuacct: Simplify the cpuacct code 2016-03-21 11:00:28 +01:00
cpudeadline.c sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed 2016-05-12 09:55:35 +02:00
cpudeadline.h sched/deadline: Unify dl_time_before() usage 2015-09-23 09:51:25 +02:00
cpufreq_schedutil.c cpufreq: schedutil: Improve prints messages with pr_fmt 2016-05-19 01:02:52 +02:00
cpufreq.c cpufreq: sched: Helpers to add and remove update_util hooks 2016-04-02 01:08:43 +02:00
cpupri.c sched/core: Use tsk_cpus_allowed() instead of accessing ->cpus_allowed 2016-05-12 09:55:35 +02:00
cpupri.h sched/cpupri: Remove unnecessary definitions in cpupri.h 2014-11-16 10:58:59 +01:00
cputime.c sched/cputime: Count actually elapsed irq & softirq time 2016-07-14 10:42:34 +02:00
deadline.c sched/core: Provide a tsk_nr_cpus_allowed() helper 2016-05-12 09:55:36 +02:00
debug.c sched/debug: Always show 'nr_migrations' 2016-06-08 14:34:49 +02:00
fair.c sched/fair: Rework throttle_count sync 2016-06-27 12:53:19 +02:00
features.h sched/fair: Convert arch_scale_cpu_capacity() from weak function to #define 2015-09-13 09:52:55 +02:00
idle_task.c locking/lockdep, sched/core: Implement a better lock pinning scheme 2016-05-05 09:23:59 +02:00
idle.c Merge branch 'sched/urgent' into sched/core, to pick up fixes 2016-06-14 11:04:13 +02:00
loadavg.c sched/loadavg: Fix loadavg artifacts on fully idle and on fully loaded systems 2016-05-12 09:55:34 +02:00
Makefile cpufreq: schedutil: New governor based on scheduler utilization data 2016-04-02 01:09:12 +02:00
rt.c sched/core: Provide a tsk_nr_cpus_allowed() helper 2016-05-12 09:55:36 +02:00
sched.h sched/fair: Rework throttle_count sync 2016-06-27 12:53:19 +02:00
stats.c sched: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
stats.h sched/debug: Fix /proc/sched_debug regression 2016-06-08 14:31:58 +02:00
stop_task.c locking/lockdep, sched/core: Implement a better lock pinning scheme 2016-05-05 09:23:59 +02:00
swait.c wait.[ch]: Introduce the simple waitqueue (swait) implementation 2016-02-25 11:27:16 +01:00
wait.c sched/wait: Fix the signal handling fix 2015-12-13 14:30:59 -08:00