Register the tsc as one persistent clock to compensate the suspend time if the tsc clocksource is always available.
Signed-off-by: Baolin Wang <[email protected]> --- arch/x86/Kconfig | 1 + arch/x86/kernel/tsc.c | 21 +++++++++++++++++++++ 2 files changed, 22 insertions(+) diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 297789a..549dd01 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -200,6 +200,7 @@ config X86 select USER_STACKTRACE_SUPPORT select VIRT_TO_BUS select X86_FEATURE_NAMES if PROC_FS + select PERSISTENT_CLOCK config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c index 74392d9..cb4f495 100644 --- a/arch/x86/kernel/tsc.c +++ b/arch/x86/kernel/tsc.c @@ -11,6 +11,7 @@ #include <linux/delay.h> #include <linux/clocksource.h> #include <linux/percpu.h> +#include <linux/persistent_clock.h> #include <linux/timex.h> #include <linux/static_key.h> @@ -1032,6 +1033,11 @@ static u64 read_tsc(struct clocksource *cs) return (u64)rdtsc_ordered(); } +static u64 notrace tsc_read_persistent_clock(void) +{ + return (u64)rdtsc_ordered(); +} + static void tsc_cs_mark_unstable(struct clocksource *cs) { if (tsc_unstable) @@ -1300,6 +1306,14 @@ static void tsc_refine_calibration_work(struct work_struct *work) if (boot_cpu_has(X86_FEATURE_ART)) art_related_clocksource = &clocksource_tsc; clocksource_register_khz(&clocksource_tsc, tsc_khz); + + if (clocksource_tsc.flags & CLOCK_SOURCE_SUSPEND_NONSTOP) { + persistent_clock_init_and_register(tsc_read_persistent_clock, + CLOCKSOURCE_MASK(64), + tsc_khz * 1000, 0); + persistent_clock_start_alarmtimer(); + } + unreg: clocksource_unregister(&clocksource_tsc_early); } @@ -1327,6 +1341,13 @@ static int __init init_tsc_clocksource(void) if (boot_cpu_has(X86_FEATURE_ART)) art_related_clocksource = &clocksource_tsc; clocksource_register_khz(&clocksource_tsc, tsc_khz); + + if (clocksource_tsc.flags & CLOCK_SOURCE_SUSPEND_NONSTOP) { + persistent_clock_init_and_register(tsc_read_persistent_clock, + CLOCKSOURCE_MASK(64), + tsc_khz * 1000, 0); + persistent_clock_start_alarmtimer(); + } unreg: clocksource_unregister(&clocksource_tsc_early); return 0; -- 1.7.9.5
