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-rw-r--r--arch/powerpc/kernel/time.c32
1 files changed, 30 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 863a5d6d9b1..9eb3284deac 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -212,23 +212,44 @@ static u64 read_purr(void)
}
/*
+ * Read the SPURR on systems that have it, otherwise the purr
+ */
+static u64 read_spurr(u64 purr)
+{
+ if (cpu_has_feature(CPU_FTR_SPURR))
+ return mfspr(SPRN_SPURR);
+ return purr;
+}
+
+/*
* Account time for a transition between system, hard irq
* or soft irq state.
*/
void account_system_vtime(struct task_struct *tsk)
{
- u64 now, delta;
+ u64 now, nowscaled, delta, deltascaled;
unsigned long flags;
local_irq_save(flags);
now = read_purr();
delta = now - get_paca()->startpurr;
get_paca()->startpurr = now;
+ nowscaled = read_spurr(now);
+ deltascaled = nowscaled - get_paca()->startspurr;
+ get_paca()->startspurr = nowscaled;
if (!in_interrupt()) {
+ /* deltascaled includes both user and system time.
+ * Hence scale it based on the purr ratio to estimate
+ * the system time */
+ deltascaled = deltascaled * get_paca()->system_time /
+ (get_paca()->system_time + get_paca()->user_time);
delta += get_paca()->system_time;
get_paca()->system_time = 0;
}
account_system_time(tsk, 0, delta);
+ get_paca()->purrdelta = delta;
+ account_system_time_scaled(tsk, deltascaled);
+ get_paca()->spurrdelta = deltascaled;
local_irq_restore(flags);
}
@@ -240,11 +261,17 @@ void account_system_vtime(struct task_struct *tsk)
*/
void account_process_vtime(struct task_struct *tsk)
{
- cputime_t utime;
+ cputime_t utime, utimescaled;
utime = get_paca()->user_time;
get_paca()->user_time = 0;
account_user_time(tsk, utime);
+
+ /* Estimate the scaled utime by scaling the real utime based
+ * on the last spurr to purr ratio */
+ utimescaled = utime * get_paca()->spurrdelta / get_paca()->purrdelta;
+ get_paca()->spurrdelta = get_paca()->purrdelta = 0;
+ account_user_time_scaled(tsk, utimescaled);
}
static void account_process_time(struct pt_regs *regs)
@@ -266,6 +293,7 @@ struct cpu_purr_data {
int initialized; /* thread is running */
u64 tb; /* last TB value read */
u64 purr; /* last PURR value read */
+ u64 spurr; /* last SPURR value read */
};
/*