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authorIsaku Yamahata <yamahata@valinux.co.jp>2009-03-04 21:05:40 +0900
committerTony Luck <tony.luck@intel.com>2009-03-26 10:50:42 -0700
commitf927da178671a824cf6c530f0623544206387e57 (patch)
treefb9178ff79bfd9ee3b396ff20018eacbfb222d47 /arch/ia64/kernel
parent496203b15b7249599712525c2b6aafe231b4628d (diff)
downloadblackbird-obmc-linux-f927da178671a824cf6c530f0623544206387e57.tar.gz
blackbird-obmc-linux-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')
-rw-r--r--arch/ia64/kernel/head.S10
-rw-r--r--arch/ia64/kernel/paravirt.c1
-rw-r--r--arch/ia64/kernel/time.c9
3 files changed, 18 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)
diff --git a/arch/ia64/kernel/paravirt.c b/arch/ia64/kernel/paravirt.c
index 9f14c16f6369..6bc33a6db755 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 f0ebb342409d..c323c7b9c775 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -50,6 +50,15 @@ 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();
+}
+#endif
+
+#ifdef CONFIG_PARAVIRT
static void
paravirt_clocksource_resume(void)
{
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