alistair23-linux/drivers/hv/Kconfig
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

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# SPDX-License-Identifier: GPL-2.0
menu "Microsoft Hyper-V guest support"
config HYPERV
tristate "Microsoft Hyper-V client drivers"
depends on X86 && ACPI && X86_LOCAL_APIC && HYPERVISOR_GUEST
select PARAVIRT
select X86_HV_CALLBACK_VECTOR
help
Select this option to run Linux as a Hyper-V client operating
system.
config HYPERV_TIMER
def_bool HYPERV
config HYPERV_UTILS
tristate "Microsoft Hyper-V Utilities driver"
depends on HYPERV && CONNECTOR && NLS
help
Select this option to enable the Hyper-V Utilities.
config HYPERV_BALLOON
tristate "Microsoft Hyper-V Balloon driver"
depends on HYPERV
help
Select this option to enable Hyper-V Balloon driver.
endmenu