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linux-brain/include/clocksource
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Vitaly Kuznetsov 3e2d94535a clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit 
There is no particular reason to not enable TSC page clocksource on
32-bit. mul_u64_u64_shr() is available and despite the increased
computational complexity (compared to 64bit) TSC page is still a huge win
compared to MSR-based clocksource.

In-kernel reads:
  MSR based clocksource: 3361 cycles
  TSC page clocksource: 49 cycles

Reads from userspace (utilizing vDSO in case of TSC page):
  MSR based clocksource: 5664 cycles
  TSC page clocksource: 131 cycles

Enabling TSC page on 32bits allows to get rid of CONFIG_HYPERV_TSCPAGE as
it is now not any different from CONFIG_HYPERV_TIMER.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lkml.kernel.org/r/20190822083630.17059-1-vkuznets@redhat.com
 		2019-08-23 16:59:54 +02:00
..
arm_arch_timer.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
hyperv_timer.h clocksource/drivers/hyperv: Enable TSC page clocksource on 32bit 2019-08-23 16:59:54 +02:00
pxa.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
samsung_pwm.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
timer-davinci.h clocksource/drivers/davinci: Add support for clockevents 2019-06-25 20:46:14 +02:00
timer-sp804.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
timer-ti-dm.h clocksource: timer-ti-dm: Make unexported functions static 2018-02-28 13:38:10 -08:00