Messages in this thread | | | Subject | Re: [PATCH v7 6/6] x86/tsc: use tsc early | From | Dou Liyang <> | Date | Wed, 8 Nov 2017 17:17:24 +0800 |
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Hi Pavel,
Sorry to reply so late.
I have tested it based on tip tree. it is OK for me.
some concerns below.
At 11/03/2017 01:26 AM, Pavel Tatashin wrote: > tsc_early_init(): > Determines offset, shift and multiplier for the early clock based on the > TSC frequency. > > tsc_early_fini() > Implement the finish part of early tsc feature, prints message about the > offset, which can be useful to find out how much time was spent in post and > boot manager (if TSC starts from 0 during boot) > > sched_clock_early(): > TSC based implementation of early clock. > > Call tsc_early_init() to initialize early boot time stamps functionality on > the supported x86 platforms, and call tsc_early_fini() to finish this > feature after permanent clock has been initialized. > > Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> > --- > arch/x86/include/asm/tsc.h | 4 +++ > arch/x86/kernel/setup.c | 10 ++++-- > arch/x86/kernel/time.c | 1 + > arch/x86/kernel/tsc.c | 81 ++++++++++++++++++++++++++++++++++++++++++++++ > 4 files changed, 94 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/include/asm/tsc.h b/arch/x86/include/asm/tsc.h > index f5e6f1c417df..6dc9618b24e3 100644 > --- a/arch/x86/include/asm/tsc.h > +++ b/arch/x86/include/asm/tsc.h > @@ -50,11 +50,15 @@ extern bool tsc_store_and_check_tsc_adjust(bool bootcpu); > extern void tsc_verify_tsc_adjust(bool resume); > extern void check_tsc_sync_source(int cpu); > extern void check_tsc_sync_target(void); > +void tsc_early_init(unsigned int khz); > +void tsc_early_fini(void); > #else > static inline bool tsc_store_and_check_tsc_adjust(bool bootcpu) { return false; } > static inline void tsc_verify_tsc_adjust(bool resume) { } > static inline void check_tsc_sync_source(int cpu) { } > static inline void check_tsc_sync_target(void) { } > +static inline void tsc_early_init(unsigned int khz) { } > +static inline void tsc_early_fini(void) { } > #endif > > extern int notsc_setup(char *); > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 0957dd73d127..3df8be642b80 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -822,7 +822,11 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) > return 0; > } > > -static void __init simple_udelay_calibration(void) > +/* > + * Initialize early tsc to show early boot timestamps, and also loops_per_jiffy > + * for udelay > + */ > +static void __init early_clock_calibration(void) > { > unsigned int tsc_khz, cpu_khz; > unsigned long lpj; > @@ -837,6 +841,8 @@ static void __init simple_udelay_calibration(void) > if (!tsc_khz) > return; > > + tsc_early_init(tsc_khz); > + > lpj = tsc_khz * 1000; > do_div(lpj, HZ); > loops_per_jiffy = lpj; > @@ -1049,7 +1055,7 @@ void __init setup_arch(char **cmdline_p) > */ > init_hypervisor_platform(); > > - simple_udelay_calibration(); > + early_clock_calibration(); > > x86_init.resources.probe_roms(); > > diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c > index 3104c5304529..838c5980cae4 100644 > --- a/arch/x86/kernel/time.c > +++ b/arch/x86/kernel/time.c > @@ -86,6 +86,7 @@ static __init void x86_late_time_init(void) > { > x86_init.timers.timer_init(); > tsc_init(); > + tsc_early_fini();
Can we put this into tsc_init(), So we can remove the definitions in tsc.h
> } > > /* > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 1c4502a2b7b2..edacd0aa55f5 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -181,6 +181,80 @@ static void set_cyc2ns_scale(unsigned long khz, int cpu, unsigned long long tsc_ > local_irq_restore(flags); > } > > +#ifdef CONFIG_X86_TSC > +static struct cyc2ns_data cyc2ns_early; > + > +static u64 sched_clock_early(void)
This function is only called during boot time. Should it be a "__init" function too?
Thanks dou.
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