add sched_clock() hook to paravirtualize sched_clock(). ia64 sched_clock() is based on ar.itc which isn't stable on virtualized environment because vcpu may move around on pcpus. So it needs paravirtualization. Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx> --- arch/ia64/include/asm/paravirt.h | 7 +++++++ arch/ia64/include/asm/timex.h | 1 + arch/ia64/kernel/head.S | 4 ++-- arch/ia64/kernel/paravirt.c | 1 + arch/ia64/kernel/time.c | 12 ++++++++++++ 5 files changed, 23 insertions(+), 2 deletions(-) diff --git a/arch/ia64/include/asm/paravirt.h b/arch/ia64/include/asm/paravirt.h index 56f69f9..a73e77a 100644 --- a/arch/ia64/include/asm/paravirt.h +++ b/arch/ia64/include/asm/paravirt.h @@ -225,6 +225,8 @@ struct pv_time_ops { int (*do_steal_accounting)(unsigned long *new_itm); void (*clocksource_resume)(void); + + unsigned long long (*sched_clock)(void); }; extern struct pv_time_ops pv_time_ops; @@ -242,6 +244,11 @@ paravirt_do_steal_accounting(unsigned long *new_itm) return pv_time_ops.do_steal_accounting(new_itm); } +static inline unsigned long long paravirt_sched_clock(void) +{ + return pv_time_ops.sched_clock(); +} + #endif /* !__ASSEMBLY__ */ #else diff --git a/arch/ia64/include/asm/timex.h b/arch/ia64/include/asm/timex.h index 4e03cfe..86c7db8 100644 --- a/arch/ia64/include/asm/timex.h +++ b/arch/ia64/include/asm/timex.h @@ -40,5 +40,6 @@ get_cycles (void) } extern void ia64_cpu_local_tick (void); +extern unsigned long long ia64_native_sched_clock (void); #endif /* _ASM_IA64_TIMEX_H */ diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index 66e491d..ca1336a 100644 --- a/arch/ia64/kernel/head.S +++ b/arch/ia64/kernel/head.S @@ -1050,7 +1050,7 @@ END(ia64_delay_loop) * except that the multiplication and the shift are done with 128-bit * intermediate precision so that we can produce a full 64-bit result. */ -GLOBAL_ENTRY(sched_clock) +GLOBAL_ENTRY(ia64_native_sched_clock) addl r8=THIS_CPU(cpu_info) + IA64_CPUINFO_NSEC_PER_CYC_OFFSET,r0 mov.m r9=ar.itc // fetch cycle-counter (35 cyc) ;; @@ -1066,7 +1066,7 @@ GLOBAL_ENTRY(sched_clock) ;; shrp r8=r9,r8,IA64_NSEC_PER_CYC_SHIFT br.ret.sptk.many rp -END(sched_clock) +END(ia64_native_sched_clock) #ifdef CONFIG_VIRT_CPU_ACCOUNTING GLOBAL_ENTRY(cycle_to_cputime) diff --git a/arch/ia64/kernel/paravirt.c b/arch/ia64/kernel/paravirt.c index de35d8e..6ebbcc1 100644 --- a/arch/ia64/kernel/paravirt.c +++ b/arch/ia64/kernel/paravirt.c @@ -366,4 +366,5 @@ ia64_native_do_steal_accounting(unsigned long *new_itm) struct pv_time_ops pv_time_ops = { .do_steal_accounting = ia64_native_do_steal_accounting, + .sched_clock = ia64_native_sched_clock, }; diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 65c10a4..6f6ca42 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -50,6 +50,18 @@ EXPORT_SYMBOL(last_cli_ip); #endif #ifdef CONFIG_PARAVIRT +/* We need to define a real function for sched_clock, to override the + weak default version */ +unsigned long long sched_clock(void) +{ + return paravirt_sched_clock(); +} +#else +unsigned long long +sched_clock(void) __attribute__((alias("ia64_native_sched_clock"))); +#endif + +#ifdef CONFIG_PARAVIRT static void paravirt_clocksource_resume(void) { -- 1.6.0.2 -- To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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