[PATCH 3/4] cputime/powerpc/s390: make scaled cputime arch specific

Stanislaw Gruszka
2016-10-31T12:36:28Z

Only s390 and powerpc have hardware facilities allowing to measure
cputimes scaled by frequency. On all other architectures
utimescaled/stimescaled are equal to utime/stime (however they are
accounted separately).

Patch remove {u,s}timescaled accounting on all architectures except
powerpc and s390, where those values are explicitly accounted on proper
places.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
---
arch/ia64/kernel/time.c | 4 +-
arch/powerpc/Kconfig | 1 +
arch/powerpc/kernel/time.c | 6 +++-
arch/s390/Kconfig | 1 +
arch/s390/kernel/vtime.c | 9 ++++--
include/linux/kernel_stat.h | 4 +-
include/linux/sched.h | 23 ++++++++++++----
kernel/fork.c | 2 +
kernel/sched/cputime.c | 61 ++++++++++--------------------------------
9 files changed, 50 insertions(+), 61 deletions(-)

diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 6f892b9..021f44a 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -68,7 +68,7 @@ void vtime_account_user(struct task_struct *tsk)

if (ti->ac_utime) {
delta_utime = cycle_to_cputime(ti->ac_utime);
- account_user_time(tsk, delta_utime, delta_utime);
+ account_user_time(tsk, delta_utime);
ti->ac_utime = 0;
}
}
@@ -112,7 +112,7 @@ void vtime_account_system(struct task_struct *tsk)
{
cputime_t delta = vtime_delta(tsk);

- account_system_time(tsk, 0, delta, delta);
+ account_system_time(tsk, 0, delta);
}
EXPORT_SYMBOL_GPL(vtime_account_system);

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 65fba4c..c7f120a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -160,6 +160,7 @@ config PPC
select HAVE_LIVEPATCH if HAVE_DYNAMIC_FTRACE_WITH_REGS
select GENERIC_CPU_AUTOPROBE
select HAVE_VIRT_CPU_ACCOUNTING
+ select ARCH_HAS_SCALED_CPUTIME if VIRT_CPU_ACCOUNTING_NATIVE
select HAVE_ARCH_HARDENED_USERCOPY
select HAVE_KERNEL_GZIP

diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 8105198..be9751f 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -358,7 +358,8 @@ void vtime_account_system(struct task_struct *tsk)
unsigned long delta, sys_scaled, stolen;

delta = vtime_delta(tsk, &sys_scaled, &stolen);
- account_system_time(tsk, 0, delta, sys_scaled);
+ account_system_time(tsk, 0, delta);
+ tsk->stimescaled += sys_scaled;
if (stolen)
account_steal_time(stolen);
}
@@ -391,7 +392,8 @@ void vtime_account_user(struct task_struct *tsk)
acct->user_time = 0;
acct->user_time_scaled = 0;
acct->utime_sspurr = 0;
- account_user_time(tsk, utime, utimescaled);
+ account_user_time(tsk, utime);
+ tsk->utimescaled += utimescaled;
}

#ifdef CONFIG_PPC32
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 426481d..028f97b 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -171,6 +171,7 @@ config S390
select SYSCTL_EXCEPTION_TRACE
select TTY
select VIRT_CPU_ACCOUNTING
+ select ARCH_HAS_SCALED_CPUTIME
select VIRT_TO_BUS
select HAVE_NMI

diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 856e30d..90eeb7c 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -137,8 +137,10 @@ static int do_account_vtime(struct task_struct *tsk, int hardirq_offset)
user_scaled = (user_scaled * mult) / div;
system_scaled = (system_scaled * mult) / div;
}
- account_user_time(tsk, user, user_scaled);
- account_system_time(tsk, hardirq_offset, system, system_scaled);
+ account_user_time(tsk, user);
+ tsk->utimescaled += user_scaled;
+ account_system_time(tsk, hardirq_offset, system)
+ tsk->stimescaled += system_scaled;

steal = S390_lowcore.steal_timer;
if ((s64) steal > 0) {
@@ -202,7 +204,8 @@ void vtime_account_irq_enter(struct task_struct *tsk)

system_scaled = (system_scaled * mult) / div;
}
- account_system_time(tsk, 0, system, system_scaled);
+ account_system_time(tsk, 0, system);
+ tsk->stimescaled += system_scaled;

virt_timer_forward(system);
}
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 44fda64..00f7768 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -78,8 +78,8 @@ static inline unsigned int kstat_cpu_irqs_sum(unsigned int cpu)
return kstat_cpu(cpu).irqs_sum;
}

-extern void account_user_time(struct task_struct *, cputime_t, cputime_t);
-extern void account_system_time(struct task_struct *, int, cputime_t, cputime_t);
+extern void account_user_time(struct task_struct *, cputime_t);
+extern void account_system_time(struct task_struct *, int, cputime_t);
extern void account_steal_time(cputime_t);
extern void account_idle_time(cputime_t);

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 348f51b..36a2c2e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1627,7 +1627,10 @@ struct task_struct {
int __user *set_child_tid; /* CLONE_CHILD_SETTID */
int __user *clear_child_tid; /* CLONE_CHILD_CLEARTID */

- cputime_t utime, stime, utimescaled, stimescaled;
+ cputime_t utime, stime;
+#ifdef ARCH_HAS_SCALED_CPUTIME
+ cputime_t utimescaled, stimescaled;
+#endif
cputime_t gtime;
struct prev_cputime prev_cputime;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
@@ -2220,8 +2223,6 @@ static inline void put_task_struct(struct task_struct *t)
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
extern void task_cputime(struct task_struct *t,
cputime_t *utime, cputime_t *stime);
-extern void task_cputime_scaled(struct task_struct *t,
- cputime_t *utimescaled, cputime_t *stimescaled);
extern cputime_t task_gtime(struct task_struct *t);
#else
static inline void task_cputime(struct task_struct *t,
@@ -2233,6 +2234,13 @@ static inline void task_cputime(struct task_struct *t,
*stime = t->stime;
}

+static inline cputime_t task_gtime(struct task_struct *t)
+{
+ return t->gtime;
+}
+#endif
+
+#ifdef ARCH_HAS_SCALED_CPUTIME
static inline void task_cputime_scaled(struct task_struct *t,
cputime_t *utimescaled,
cputime_t *stimescaled)
@@ -2242,12 +2250,15 @@ static inline void task_cputime_scaled(struct task_struct *t,
if (stimescaled)
*stimescaled = t->stimescaled;
}
-
-static inline cputime_t task_gtime(struct task_struct *t)
+#else
+static inline void task_cputime_scaled(struct task_struct *t,
+ cputime_t *utimescaled,
+ cputime_t *stimescaled)
{
- return t->gtime;
+ task_cputime(t, utimescaled, stimescaled);
}
#endif
+
extern void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);
extern void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st);

diff --git a/kernel/fork.c b/kernel/fork.c
index 623259f..dbc9f60 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1548,7 +1548,9 @@ static void posix_cpu_timers_init(struct task_struct *tsk)
init_sigpending(&p->pending);

p->utime = p->stime = p->gtime = 0;
+#ifdef ARCH_HAS_SCALED_CPUTIME
p->utimescaled = p->stimescaled = 0;
+#endif
prev_cputime_init(&p->prev_cputime);

#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 3229c72..d427def 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -128,16 +128,13 @@ static inline void task_group_account_field(struct task_struct *p, int index,
* Account user cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in user space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
*/
-void account_user_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
+void account_user_time(struct task_struct *p, cputime_t cputime)
{
int index;

/* Add user time to process. */
p->utime += cputime;
- p->utimescaled += cputime_scaled;
account_group_user_time(p, cputime);

index = (task_nice(p) > 0) ? CPUTIME_NICE : CPUTIME_USER;
@@ -153,16 +150,13 @@ void account_user_time(struct task_struct *p, cputime_t cputime,
* Account guest cpu time to a process.
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in virtual machine since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
*/
-static void account_guest_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled)
+static void account_guest_time(struct task_struct *p, cputime_t cputime)
{
u64 *cpustat = kcpustat_this_cpu->cpustat;

/* Add guest time to process. */
p->utime += cputime;
- p->utimescaled += cputime_scaled;
account_group_user_time(p, cputime);
p->gtime += cputime;

@@ -180,16 +174,13 @@ static void account_guest_time(struct task_struct *p, cputime_t cputime,
* Account system cpu time to a process and desired cpustat field
* @p: the process that the cpu time gets accounted to
* @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
- * @target_cputime64: pointer to cpustat field that has to be updated
+ * @index: pointer to cpustat field that has to be updated
*/
static inline
-void __account_system_time(struct task_struct *p, cputime_t cputime,
- cputime_t cputime_scaled, int index)
+void __account_system_time(struct task_struct *p, cputime_t cputime, int index)
{
/* Add system time to process. */
p->stime += cputime;
- p->stimescaled += cputime_scaled;
account_group_system_time(p, cputime);

/* Add system time to cpustat. */
@@ -204,15 +195,14 @@ void __account_system_time(struct task_struct *p, cputime_t cputime,
* @p: the process that the cpu time gets accounted to
* @hardirq_offset: the offset to subtract from hardirq_count()
* @cputime: the cpu time spent in kernel space since the last update
- * @cputime_scaled: cputime scaled by cpu frequency
*/
void account_system_time(struct task_struct *p, int hardirq_offset,
- cputime_t cputime, cputime_t cputime_scaled)
+ cputime_t cputime)
{
int index;

if ((p->flags & PF_VCPU) && (irq_count() - hardirq_offset == 0)) {
- account_guest_time(p, cputime, cputime_scaled);
+ account_guest_time(p, cputime);
return;
}

@@ -223,7 +213,7 @@ void account_system_time(struct task_struct *p, int hardirq_offset,
else
index = CPUTIME_SYSTEM;

- __account_system_time(p, cputime, cputime_scaled, index);
+ __account_system_time(p, cputime, index);
}

/*
@@ -410,15 +400,15 @@ static void irqtime_account_process_tick(struct task_struct *p, int user_tick,
* So, we have to handle it separately here.
* Also, p->stime needs to be updated for ksoftirqd.
*/
- __account_system_time(p, cputime, cputime, CPUTIME_SOFTIRQ);
+ __account_system_time(p, cputime, CPUTIME_SOFTIRQ);
} else if (user_tick) {
- account_user_time(p, cputime, cputime);
+ account_user_time(p, cputime);
} else if (p == rq->idle) {
account_idle_time(cputime);
} else if (p->flags & PF_VCPU) { /* System time or guest time */
- account_guest_time(p, cputime, cputime);
+ account_guest_time(p, cputime);
} else {
- __account_system_time(p, cputime, cputime, CPUTIME_SYSTEM);
+ __account_system_time(p, cputime CPUTIME_SYSTEM);
}
}

@@ -521,9 +511,9 @@ void account_process_tick(struct task_struct *p, int user_tick)
cputime -= steal;

if (user_tick)
- account_user_time(p, cputime, cputime);
+ account_user_time(p, cputime);
else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
- account_system_time(p, HARDIRQ_OFFSET, cputime, cputime);
+ account_system_time(p, HARDIRQ_OFFSET, cputime);
else
account_idle_time(cputime);
}
@@ -744,7 +734,7 @@ static void __vtime_account_system(struct task_struct *tsk)
{
cputime_t delta_cpu = get_vtime_delta(tsk);

- account_system_time(tsk, irq_count(), delta_cpu, delta_cpu);
+ account_system_time(tsk, irq_count(), delta_cpu);
}

void vtime_account_system(struct task_struct *tsk)
@@ -765,7 +755,7 @@ void vtime_account_user(struct task_struct *tsk)
tsk->vtime_snap_whence = VTIME_SYS;
if (vtime_delta(tsk)) {
delta_cpu = get_vtime_delta(tsk);
- account_user_time(tsk, delta_cpu, delta_cpu);
+ account_user_time(tsk, delta_cpu);
}
write_seqcount_end(&tsk->vtime_seqcount);
}
@@ -921,25 +911,4 @@ void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
if (stime)
*stime += sdelta;
}
-
-void task_cputime_scaled(struct task_struct *t,
- cputime_t *utimescaled, cputime_t *stimescaled)
-{
- cputime_t udelta, sdelta;
-
- if (!vtime_accounting_enabled()) {
- if (utimescaled)
- *utimescaled = t->utimescaled;
- if (stimescaled)
- *stimescaled = t->stimescaled;
- return;
- }
-
- fetch_task_cputime(t, utimescaled, stimescaled,
- &t->utimescaled, &t->stimescaled, &udelta, &sdelta);
- if (utimescaled)
- *utimescaled += udelta;
- if (stimescaled)
- *stimescaled += sdelta;
-}
#endif /* CONFIG_VIRT_CPU_ACCOUNTING_GEN */
--
1.7.1