On Mon, Jul 30, 2018 at 3:55 AM Dou Liyang <[email protected]> wrote: > > static_branch_enable(&__use_tsc) may be called twice in common case, that > is redundant. And there are also some common functions both in > tsc_early_init() and tsc_init(). > > Move them into a separate helper function, only call it once. > Also fix comments: > -s/authorative/authoritative > -s/cyc2ns_init/tsc_init > > Cc: Thomas Gleixner <[email protected]> > Cc: Ingo Molnar <[email protected]> > Cc: "H. Peter Anvin" <[email protected]> > Cc: Peter Zijlstra <[email protected]> > Cc: Pavel Tatashin <[email protected]> > Signed-off-by: Dou Liyang <[email protected]>
Hi Dou, Nice cleanup. Reviewed-by: Pavel Tatashin <[email protected]> Thank you, Pavel > --- > arch/x86/kernel/tsc.c | 22 ++++++++++++---------- > 1 file changed, 12 insertions(+), 10 deletions(-) > > diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c > index 02e416b87ac1..ba0a6b6e0726 100644 > --- a/arch/x86/kernel/tsc.c > +++ b/arch/x86/kernel/tsc.c > @@ -182,7 +182,7 @@ static void __init cyc2ns_init_boot_cpu(void) > } > > /* > - * Secondary CPUs do not run through cyc2ns_init(), so set up > + * Secondary CPUs do not run through tsc_init(), so set up > * all the scale factors for all CPUs, assuming the same > * speed as the bootup CPU. (cpufreq notifiers will fix this > * up if their speed diverges) > @@ -1389,7 +1389,7 @@ static bool __init determine_cpu_tsc_frequencies(bool > early) > } > > /* > - * Trust non-zero tsc_khz as authorative, > + * Trust non-zero tsc_khz as authoritative, > * and use it to sanity check cpu_khz, > * which will be off if system timer is off. > */ > @@ -1421,6 +1421,14 @@ static unsigned long __init get_loops_per_jiffy(void) > return lpj; > } > > +static void __init enable_use_tsc(void) > +{ > + /* Sanitize TSC ADJUST before cyc2ns gets initialized */ > + tsc_store_and_check_tsc_adjust(true); > + cyc2ns_init_boot_cpu(); > + static_branch_enable(&__use_tsc); > +} > + > void __init tsc_early_init(void) > { > if (!boot_cpu_has(X86_FEATURE_TSC)) > @@ -1429,10 +1437,7 @@ void __init tsc_early_init(void) > return; > loops_per_jiffy = get_loops_per_jiffy(); > > - /* Sanitize TSC ADJUST before cyc2ns gets initialized */ > - tsc_store_and_check_tsc_adjust(true); > - cyc2ns_init_boot_cpu(); > - static_branch_enable(&__use_tsc); > + enable_use_tsc(); > } > > void __init tsc_init(void) > @@ -1456,13 +1461,10 @@ void __init tsc_init(void) > setup_clear_cpu_cap(X86_FEATURE_TSC_DEADLINE_TIMER); > return; > } > - /* Sanitize TSC ADJUST before cyc2ns gets initialized */ > - tsc_store_and_check_tsc_adjust(true); > - cyc2ns_init_boot_cpu(); > + enable_use_tsc(); > } > > cyc2ns_init_secondary_cpus(); > - static_branch_enable(&__use_tsc); > > if (!no_sched_irq_time) > enable_sched_clock_irqtime(); > -- > 2.14.3 > > >
