linux_dsm_epyc7002/include
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
..
acpi Revert "ACPI, PCI, IRQ: remove redundant code in acpi_irq_penalty_init()" 2016-07-02 01:38:34 +02:00
asm-generic sched/cputime: Count actually elapsed irq & softirq time 2016-07-14 10:42:34 +02:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
drm drm/i915: Removing PCI IDs that are no longer listed as Kabylake. 2016-06-29 12:19:13 +03:00
dt-bindings Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-05-26 09:23:43 -07:00
keys
kvm arm64: KVM: fix build with CONFIG_ARM_PMU disabled 2016-06-27 12:55:51 +02:00
linux Merge branch 'sched/core' into timers/nohz, to avoid conflicts in upcoming patches 2016-07-14 10:37:48 +02:00
math-emu
media Update my main e-mails at the Kernel tree 2016-06-15 15:35:37 -10:00
memory
misc cxl: Add kernel API to allow a context to operate with relocate disabled 2016-05-11 21:54:10 +10:00
net bonding: prevent out of bound accesses 2016-07-01 06:06:09 -04:00
pcmcia
ras
rdma IB/rdmavt: Correct qp_priv_alloc() return value test 2016-06-23 10:16:15 -04:00
rxrpc
scsi
soc ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
sound ASoC: Updates for v4.7 2016-05-16 14:59:00 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
trace - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00
uapi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse 2016-07-03 12:02:00 -07:00
video imx-drm probing fix 2016-05-25 12:36:20 +10:00
xen
Kbuild