The following commit has been merged into the timers/core branch of tip: Commit-ID: 3e2d94535adb2df15f3907e4b4c7cd8a5a4c2b5a Gitweb: https://git.kernel.org/tip/3e2d94535adb2df15f3907e4b4c7cd8a5a4c2b5a Author: Vitaly Kuznetsov <vkuzn...@redhat.com> AuthorDate: Thu, 22 Aug 2019 10:36:30 +02:00 Committer: Thomas Gleixner <t...@linutronix.de> CommitterDate: Fri, 23 Aug 2019 16:59:54 +02:00
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 <vkuzn...@redhat.com> Signed-off-by: Thomas Gleixner <t...@linutronix.de> Reviewed-by: Michael Kelley <mikel...@microsoft.com> Link: https://lkml.kernel.org/r/20190822083630.17059-1-vkuzn...@redhat.com --- arch/x86/include/asm/vdso/gettimeofday.h | 6 +++--- drivers/clocksource/hyperv_timer.c | 11 ----------- drivers/hv/Kconfig | 3 --- include/clocksource/hyperv_timer.h | 8 +++----- 4 files changed, 6 insertions(+), 22 deletions(-) diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h index ae91429..bcbf901 100644 --- a/arch/x86/include/asm/vdso/gettimeofday.h +++ b/arch/x86/include/asm/vdso/gettimeofday.h @@ -51,7 +51,7 @@ extern struct pvclock_vsyscall_time_info pvclock_page __attribute__((visibility("hidden"))); #endif -#ifdef CONFIG_HYPERV_TSCPAGE +#ifdef CONFIG_HYPERV_TIMER extern struct ms_hyperv_tsc_page hvclock_page __attribute__((visibility("hidden"))); #endif @@ -192,7 +192,7 @@ static u64 vread_pvclock(void) } #endif -#ifdef CONFIG_HYPERV_TSCPAGE +#ifdef CONFIG_HYPERV_TIMER static u64 vread_hvclock(void) { return hv_read_tsc_page(&hvclock_page); @@ -215,7 +215,7 @@ static inline u64 __arch_get_hw_counter(s32 clock_mode) return vread_pvclock(); } #endif -#ifdef CONFIG_HYPERV_TSCPAGE +#ifdef CONFIG_HYPERV_TIMER if (clock_mode == VCLOCK_HVCLOCK) { barrier(); return vread_hvclock(); diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index c322ab4..2317d4e 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -213,8 +213,6 @@ EXPORT_SYMBOL_GPL(hv_stimer_global_cleanup); struct clocksource *hyperv_cs; EXPORT_SYMBOL_GPL(hyperv_cs); -#ifdef CONFIG_HYPERV_TSCPAGE - static struct ms_hyperv_tsc_page tsc_pg __aligned(PAGE_SIZE); struct ms_hyperv_tsc_page *hv_get_tsc_page(void) @@ -245,7 +243,6 @@ static struct clocksource hyperv_cs_tsc = { .mask = CLOCKSOURCE_MASK(64), .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -#endif static u64 notrace read_hv_clock_msr(struct clocksource *arg) { @@ -272,7 +269,6 @@ static struct clocksource hyperv_cs_msr = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; -#ifdef CONFIG_HYPERV_TSCPAGE static bool __init hv_init_tsc_clocksource(void) { u64 tsc_msr; @@ -304,13 +300,6 @@ static bool __init hv_init_tsc_clocksource(void) return true; } -#else -static bool __init hv_init_tsc_clocksource(void) -{ - return false; -} -#endif - void __init hv_init_clocksource(void) { diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig index 9a59957..79e5356 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 diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index a821deb..422f5e5 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -28,12 +28,10 @@ extern void hv_stimer_cleanup(unsigned int cpu); extern void hv_stimer_global_cleanup(void); extern void hv_stimer0_isr(void); -#if IS_ENABLED(CONFIG_HYPERV) +#ifdef CONFIG_HYPERV_TIMER extern struct clocksource *hyperv_cs; extern void hv_init_clocksource(void); -#endif /* CONFIG_HYPERV */ -#ifdef CONFIG_HYPERV_TSCPAGE extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); static inline notrace u64 @@ -91,7 +89,7 @@ hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) return hv_read_tsc_page_tsc(tsc_pg, &cur_tsc); } -#else /* CONFIG_HYPERV_TSC_PAGE */ +#else /* CONFIG_HYPERV_TIMER */ static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { return NULL; @@ -102,6 +100,6 @@ static inline u64 hv_read_tsc_page_tsc(const struct ms_hyperv_tsc_page *tsc_pg, { return U64_MAX; } -#endif /* CONFIG_HYPERV_TSCPAGE */ +#endif /* CONFIG_HYPERV_TIMER */ #endif
