powerpc/time: isolate scaled cputime accounting in dedicated functions.

scaled cputime is only meaningfull when the processor has
SPURR and/or PURR, which means only on PPC64.

In preparation of the following patch that will remove
CONFIG_ARCH_HAS_SCALED_CPUTIME on PPC32, this patch moves
all scaled cputing accounting logic into dedicated functions.

This patch doesn't change any functionality. It's only code
reorganisation.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 68e8f963d108cf3e31463277695ffdfd1aea369e..cf0d5c2834d083bebe4c89b96b7c74271e5898e6 100644 (file)
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -282,26 +282,16 @@ static inline u64 calculate_stolen_time(u64 stop_tb)
  * Account time for a transition between system, hard irq
  * or soft irq state.
  */
-static unsigned long vtime_delta(struct task_struct *tsk,
-                                unsigned long *stime_scaled,
-                                unsigned long *steal_time)
+static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
+                                       unsigned long now, unsigned long stime)
 {
-       unsigned long now, nowscaled, deltascaled;
-       unsigned long stime;
+       unsigned long stime_scaled;
+       unsigned long nowscaled, deltascaled;
        unsigned long utime, utime_scaled;
-       struct cpu_accounting_data *acct = get_accounting(tsk);
 
-       WARN_ON_ONCE(!irqs_disabled());
-
-       now = mftb();
        nowscaled = read_spurr(now);
-       stime = now - acct->starttime;
-       acct->starttime = now;
        deltascaled = nowscaled - acct->startspurr;
        acct->startspurr = nowscaled;
-
-       *steal_time = calculate_stolen_time(now);
-
        utime = acct->utime - acct->utime_sspurr;
        acct->utime_sspurr = acct->utime;
 
@@ -315,18 +305,38 @@ static unsigned long vtime_delta(struct task_struct *tsk,
         * the user ticks get saved up in paca->user_time_scaled to be
         * used by account_process_tick.
         */
-       *stime_scaled = stime;
+       stime_scaled = stime;
        utime_scaled = utime;
        if (deltascaled != stime + utime) {
                if (utime) {
-                       *stime_scaled = deltascaled * stime / (stime + utime);
-                       utime_scaled = deltascaled - *stime_scaled;
+                       stime_scaled = deltascaled * stime / (stime + utime);
+                       utime_scaled = deltascaled - stime_scaled;
                } else {
-                       *stime_scaled = deltascaled;
+                       stime_scaled = deltascaled;
                }
        }
        acct->utime_scaled += utime_scaled;
 
+       return stime_scaled;
+}
+
+static unsigned long vtime_delta(struct task_struct *tsk,
+                                unsigned long *stime_scaled,
+                                unsigned long *steal_time)
+{
+       unsigned long now, stime;
+       struct cpu_accounting_data *acct = get_accounting(tsk);
+
+       WARN_ON_ONCE(!irqs_disabled());
+
+       now = mftb();
+       stime = now - acct->starttime;
+       acct->starttime = now;
+
+       *stime_scaled = vtime_delta_scaled(acct, now, stime);
+
+       *steal_time = calculate_stolen_time(now);
+
        return stime;
 }
 
@@ -365,6 +375,19 @@ void vtime_account_idle(struct task_struct *tsk)
        acct->idle_time += stime + steal_time;
 }
 
+static void vtime_flush_scaled(struct task_struct *tsk,
+                              struct cpu_accounting_data *acct)
+{
+       if (acct->utime_scaled)
+               tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
+       if (acct->stime_scaled)
+               tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
+
+       acct->utime_scaled = 0;
+       acct->utime_sspurr = 0;
+       acct->stime_scaled = 0;
+}
+
 /*
  * Account the whole cputime accumulated in the paca
  * Must be called with interrupts disabled.
@@ -379,9 +402,6 @@ void vtime_flush(struct task_struct *tsk)
        if (acct->utime)
                account_user_time(tsk, cputime_to_nsecs(acct->utime));
 
-       if (acct->utime_scaled)
-               tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
-
        if (acct->gtime)
                account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
 
@@ -394,8 +414,6 @@ void vtime_flush(struct task_struct *tsk)
        if (acct->stime)
                account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
                                          CPUTIME_SYSTEM);
-       if (acct->stime_scaled)
-               tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
 
        if (acct->hardirq_time)
                account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
@@ -404,14 +422,13 @@ void vtime_flush(struct task_struct *tsk)
                account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
                                          CPUTIME_SOFTIRQ);
 
+       vtime_flush_scaled(tsk, acct);
+
        acct->utime = 0;
-       acct->utime_scaled = 0;
-       acct->utime_sspurr = 0;
        acct->gtime = 0;
        acct->steal_time = 0;
        acct->idle_time = 0;
        acct->stime = 0;
-       acct->stime_scaled = 0;
        acct->hardirq_time = 0;
        acct->softirq_time = 0;
 }