kernel_optimize_test/include
Julien Thierry 7b77452ec5 arm64: use WFE for long delays
The current delay implementation uses the yield instruction, which is a
hint that it is beneficial to schedule another thread. As this is a hint,
it may be implemented as a NOP, causing all delays to be busy loops. This
is the case for many existing CPUs.

Taking advantage of the generic timer sending periodic events to all
cores, we can use WFE during delays to reduce power consumption. This is
beneficial only for delays longer than the period of the timer event
stream.

If timer event stream is not enabled, delays will behave as yield/busy
loops.

Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2017-10-13 18:56:15 +01:00
..
acpi ACPI / bus: Make ACPI_HANDLE() work for non-GPL code again 2017-09-19 22:42:31 +02:00
asm-generic Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 20:01:41 -07:00
clocksource arm64: use WFE for long delays 2017-10-13 18:56:15 +01:00
crypto
drm
dt-bindings Merge branch '4.14-features' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-09-15 20:43:33 -07:00
keys
kvm
linux Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-10-01 13:03:16 -07:00
math-emu
media
memory
misc
net net: prevent dst uses after free 2017-09-21 20:42:15 -07:00
pcmcia
ras
rdma IB: Correct MR length field to be 64-bit 2017-09-25 11:47:23 -04:00
scsi SCSI misc on 20170913 2017-09-13 10:47:14 -07:00
soc ARM: SoC driver updates for v4.14 2017-09-10 20:40:00 -07:00
sound
target
trace sched/debug: Add explicit TASK_PARKED printing 2017-09-29 11:02:57 +02:00
uapi IB/core: Fix typo in the name of the tag-matching cap struct 2017-09-25 11:47:23 -04:00
video
xen xen, arm64: drop dummy lookup_address() 2017-09-19 09:25:05 -04:00