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authorVitaly Kuznetsov <vkuznets@redhat.com>2019-08-22 10:36:30 +0200
committerThomas Gleixner <tglx@linutronix.de>2019-08-23 16:59:54 +0200
commit3e2d94535adb2df15f3907e4b4c7cd8a5a4c2b5a (patch)
treeaa53940e9cf060d6afd783cdaeea0a998101722a /drivers/hv
parentbd00cd52d5be655a2f217e2ed74b91a71cb2b14f (diff)
downloadlinux-3e2d94535adb2df15f3907e4b4c7cd8a5a4c2b5a.tar.bz2
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
Diffstat (limited to 'drivers/hv')
-rw-r--r--drivers/hv/Kconfig3
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 9a59957922d4..79e5356a737a 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -14,9 +14,6 @@ config HYPERV
config HYPERV_TIMER
def_bool HYPERV
-config HYPERV_TSCPAGE
- def_bool HYPERV && X86_64
-
config HYPERV_UTILS
tristate "Microsoft Hyper-V Utilities driver"
depends on HYPERV && CONNECTOR && NLS