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authorIsaku Yamahata <yamahata@valinux.co.jp>2009-03-04 07:05:40 -0500
committerTony Luck <tony.luck@intel.com>2009-03-26 13:50:42 -0400
commitf927da178671a824cf6c530f0623544206387e57 (patch)
treefb9178ff79bfd9ee3b396ff20018eacbfb222d47 /arch/ia64/kernel/head.S
parent496203b15b7249599712525c2b6aafe231b4628d (diff)
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.S10
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)
1050 * except that the multiplication and the shift are done with 128-bit 1050 * except that the multiplication and the shift are done with 128-bit
1051 * intermediate precision so that we can produce a full 64-bit result. 1051 * intermediate precision so that we can produce a full 64-bit result.
1052 */ 1052 */
1053GLOBAL_ENTRY(sched_clock) 1053GLOBAL_ENTRY(ia64_native_sched_clock)
1054 addl r8=THIS_CPU(cpu_info) + IA64_CPUINFO_NSEC_PER_CYC_OFFSET,r0 1054 addl r8=THIS_CPU(cpu_info) + IA64_CPUINFO_NSEC_PER_CYC_OFFSET,r0
1055 mov.m r9=ar.itc // fetch cycle-counter (35 cyc) 1055 mov.m r9=ar.itc // fetch cycle-counter (35 cyc)
1056 ;; 1056 ;;
@@ -1066,7 +1066,13 @@ GLOBAL_ENTRY(sched_clock)
1066 ;; 1066 ;;
1067 shrp r8=r9,r8,IA64_NSEC_PER_CYC_SHIFT 1067 shrp r8=r9,r8,IA64_NSEC_PER_CYC_SHIFT
1068 br.ret.sptk.many rp 1068 br.ret.sptk.many rp
1069END(sched_clock) 1069END(ia64_native_sched_clock)
1070#ifndef CONFIG_PARAVIRT
1071 //unsigned long long
1072 //sched_clock(void) __attribute__((alias("ia64_native_sched_clock")));
1073 .global sched_clock
1074sched_clock = ia64_native_sched_clock
1075#endif
1070 1076
1071#ifdef CONFIG_VIRT_CPU_ACCOUNTING 1077#ifdef CONFIG_VIRT_CPU_ACCOUNTING
1072GLOBAL_ENTRY(cycle_to_cputime) 1078GLOBAL_ENTRY(cycle_to_cputime)