diff options
Diffstat (limited to 'arch/powerpc/kernel/time.c')
| -rw-r--r-- | arch/powerpc/kernel/time.c | 21 |
1 files changed, 13 insertions, 8 deletions
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c index 398cd0c7b60f..85cf317c9069 100644 --- a/arch/powerpc/kernel/time.c +++ b/arch/powerpc/kernel/time.c @@ -219,7 +219,11 @@ static u64 read_purr(void) */ static u64 read_spurr(u64 purr) { - if (cpu_has_feature(CPU_FTR_SPURR)) + /* + * cpus without PURR won't have a SPURR + * We already know the former when we use this, so tell gcc + */ + if (cpu_has_feature(CPU_FTR_PURR) && cpu_has_feature(CPU_FTR_SPURR)) return mfspr(SPRN_SPURR); return purr; } @@ -230,29 +234,30 @@ static u64 read_spurr(u64 purr) */ void account_system_vtime(struct task_struct *tsk) { - u64 now, nowscaled, delta, deltascaled; + u64 now, nowscaled, delta, deltascaled, sys_time; unsigned long flags; local_irq_save(flags); now = read_purr(); - delta = now - get_paca()->startpurr; - get_paca()->startpurr = now; nowscaled = read_spurr(now); + delta = now - get_paca()->startpurr; deltascaled = nowscaled - get_paca()->startspurr; + get_paca()->startpurr = now; 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 */ + sys_time = get_paca()->system_time; if (get_paca()->user_time) - deltascaled = deltascaled * get_paca()->system_time / - (get_paca()->system_time + get_paca()->user_time); - delta += get_paca()->system_time; + deltascaled = deltascaled * sys_time / + (sys_time + get_paca()->user_time); + delta += sys_time; get_paca()->system_time = 0; } account_system_time(tsk, 0, delta); - get_paca()->purrdelta = delta; account_system_time_scaled(tsk, deltascaled); + get_paca()->purrdelta = delta; get_paca()->spurrdelta = deltascaled; local_irq_restore(flags); } |