diff options
| author |   Isaku Yamahata <yamahata@valinux.co.jp> | 2009-03-04 21:05:40 +0900 |
|---|---|---|
| committer |   Tony Luck <tony.luck@intel.com> | 2009-03-26 10:50:42 -0700 |
| commit | f927da178671a824cf6c530f0623544206387e57 (patch) | |
| tree | fb9178ff79bfd9ee3b396ff20018eacbfb222d47 /arch/ia64/kernel/head.S | |
| parent | ia64/pv_ops/xen: paravirtualize read/write ar.itc and ar.itm (diff) | |
| download | linux-dev-f927da178671a824cf6c530f0623544206387e57.tar.xz linux-dev-f927da178671a824cf6c530f0623544206387e57.zip | |
ia64/pv_ops/pv_time_ops: add sched_clock hook.
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@valinux.co.jp>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/ia64/kernel/head.S')
| -rw-r--r-- | arch/ia64/kernel/head.S | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/arch/ia64/kernel/head.S b/arch/ia64/kernel/head.S index 59301c472800..23f846de62d5 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 +1066,13 @@ 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) +#ifndef CONFIG_PARAVIRT + //unsigned long long + //sched_clock(void) __attribute__((alias("ia64_native_sched_clock"))); + .global sched_clock +sched_clock = ia64_native_sched_clock +#endif #ifdef CONFIG_VIRT_CPU_ACCOUNTING GLOBAL_ENTRY(cycle_to_cputime) |