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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2016-03-25 03:53:42 -0300
commit03dd4cb26d967f9588437b0fc9cc0e8353322bb7 (patch)
treefa581f6dc1c0596391690d1f67eceef3af8246dc /kernel/sched/cputime.c
parentd4e493caf788ef44982e131ff9c786546904d934 (diff)
Linux-libre 4.5-gnu
Diffstat (limited to 'kernel/sched/cputime.c')
-rw-r--r--kernel/sched/cputime.c130
1 files changed, 79 insertions, 51 deletions
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 05de80b48..75f98c549 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -5,6 +5,9 @@
#include <linux/static_key.h>
#include <linux/context_tracking.h>
#include "sched.h"
+#ifdef CONFIG_PARAVIRT
+#include <asm/paravirt.h>
+#endif
#ifdef CONFIG_IRQ_TIME_ACCOUNTING
@@ -259,21 +262,21 @@ static __always_inline bool steal_account_process_tick(void)
#ifdef CONFIG_PARAVIRT
if (static_key_false(&paravirt_steal_enabled)) {
u64 steal;
- cputime_t steal_ct;
+ unsigned long steal_jiffies;
steal = paravirt_steal_clock(smp_processor_id());
steal -= this_rq()->prev_steal_time;
/*
- * cputime_t may be less precise than nsecs (eg: if it's
- * based on jiffies). Lets cast the result to cputime
+ * steal is in nsecs but our caller is expecting steal
+ * time in jiffies. Lets cast the result to jiffies
* granularity and account the rest on the next rounds.
*/
- steal_ct = nsecs_to_cputime(steal);
- this_rq()->prev_steal_time += cputime_to_nsecs(steal_ct);
+ steal_jiffies = nsecs_to_jiffies(steal);
+ this_rq()->prev_steal_time += jiffies_to_nsecs(steal_jiffies);
- account_steal_time(steal_ct);
- return steal_ct;
+ account_steal_time(jiffies_to_cputime(steal_jiffies));
+ return steal_jiffies;
}
#endif
return false;
@@ -466,7 +469,7 @@ void account_process_tick(struct task_struct *p, int user_tick)
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
struct rq *rq = this_rq();
- if (vtime_accounting_enabled())
+ if (vtime_accounting_cpu_enabled())
return;
if (sched_clock_irqtime) {
@@ -665,26 +668,25 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
-static unsigned long long vtime_delta(struct task_struct *tsk)
+static cputime_t vtime_delta(struct task_struct *tsk)
{
- unsigned long long clock;
+ unsigned long now = READ_ONCE(jiffies);
- clock = local_clock();
- if (clock < tsk->vtime_snap)
+ if (time_before(now, (unsigned long)tsk->vtime_snap))
return 0;
- return clock - tsk->vtime_snap;
+ return jiffies_to_cputime(now - tsk->vtime_snap);
}
static cputime_t get_vtime_delta(struct task_struct *tsk)
{
- unsigned long long delta = vtime_delta(tsk);
+ unsigned long now = READ_ONCE(jiffies);
+ unsigned long delta = now - tsk->vtime_snap;
- WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_SLEEPING);
- tsk->vtime_snap += delta;
+ WARN_ON_ONCE(tsk->vtime_snap_whence == VTIME_INACTIVE);
+ tsk->vtime_snap = now;
- /* CHECKME: always safe to convert nsecs to cputime? */
- return nsecs_to_cputime(delta);
+ return jiffies_to_cputime(delta);
}
static void __vtime_account_system(struct task_struct *tsk)
@@ -696,37 +698,44 @@ static void __vtime_account_system(struct task_struct *tsk)
void vtime_account_system(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ if (!vtime_delta(tsk))
+ return;
+
+ write_seqcount_begin(&tsk->vtime_seqcount);
__vtime_account_system(tsk);
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_gen_account_irq_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
- __vtime_account_system(tsk);
+ write_seqcount_begin(&tsk->vtime_seqcount);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
if (context_tracking_in_user())
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_account_user(struct task_struct *tsk)
{
cputime_t delta_cpu;
- write_seqlock(&tsk->vtime_seqlock);
- delta_cpu = get_vtime_delta(tsk);
+ write_seqcount_begin(&tsk->vtime_seqcount);
tsk->vtime_snap_whence = VTIME_SYS;
- account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
- write_sequnlock(&tsk->vtime_seqlock);
+ if (vtime_delta(tsk)) {
+ delta_cpu = get_vtime_delta(tsk);
+ account_user_time(tsk, delta_cpu, cputime_to_scaled(delta_cpu));
+ }
+ write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_user_enter(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
- __vtime_account_system(tsk);
+ write_seqcount_begin(&tsk->vtime_seqcount);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
tsk->vtime_snap_whence = VTIME_USER;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seqcount);
}
void vtime_guest_enter(struct task_struct *tsk)
@@ -738,19 +747,20 @@ void vtime_guest_enter(struct task_struct *tsk)
* synchronization against the reader (task_gtime())
* that can thus safely catch up with a tickless delta.
*/
- write_seqlock(&tsk->vtime_seqlock);
- __vtime_account_system(tsk);
+ write_seqcount_begin(&tsk->vtime_seqcount);
+ if (vtime_delta(tsk))
+ __vtime_account_system(tsk);
current->flags |= PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seqcount);
}
EXPORT_SYMBOL_GPL(vtime_guest_enter);
void vtime_guest_exit(struct task_struct *tsk)
{
- write_seqlock(&tsk->vtime_seqlock);
+ write_seqcount_begin(&tsk->vtime_seqcount);
__vtime_account_system(tsk);
current->flags &= ~PF_VCPU;
- write_sequnlock(&tsk->vtime_seqlock);
+ write_seqcount_end(&tsk->vtime_seqcount);
}
EXPORT_SYMBOL_GPL(vtime_guest_exit);
@@ -763,24 +773,26 @@ void vtime_account_idle(struct task_struct *tsk)
void arch_vtime_task_switch(struct task_struct *prev)
{
- write_seqlock(&prev->vtime_seqlock);
- prev->vtime_snap_whence = VTIME_SLEEPING;
- write_sequnlock(&prev->vtime_seqlock);
+ write_seqcount_begin(&prev->vtime_seqcount);
+ prev->vtime_snap_whence = VTIME_INACTIVE;
+ write_seqcount_end(&prev->vtime_seqcount);
- write_seqlock(&current->vtime_seqlock);
+ write_seqcount_begin(&current->vtime_seqcount);
current->vtime_snap_whence = VTIME_SYS;
- current->vtime_snap = sched_clock_cpu(smp_processor_id());
- write_sequnlock(&current->vtime_seqlock);
+ current->vtime_snap = jiffies;
+ write_seqcount_end(&current->vtime_seqcount);
}
void vtime_init_idle(struct task_struct *t, int cpu)
{
unsigned long flags;
- write_seqlock_irqsave(&t->vtime_seqlock, flags);
+ local_irq_save(flags);
+ write_seqcount_begin(&t->vtime_seqcount);
t->vtime_snap_whence = VTIME_SYS;
- t->vtime_snap = sched_clock_cpu(cpu);
- write_sequnlock_irqrestore(&t->vtime_seqlock, flags);
+ t->vtime_snap = jiffies;
+ write_seqcount_end(&t->vtime_seqcount);
+ local_irq_restore(flags);
}
cputime_t task_gtime(struct task_struct *t)
@@ -788,17 +800,17 @@ cputime_t task_gtime(struct task_struct *t)
unsigned int seq;
cputime_t gtime;
- if (!context_tracking_is_enabled())
+ if (!vtime_accounting_enabled())
return t->gtime;
do {
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seqcount);
gtime = t->gtime;
- if (t->flags & PF_VCPU)
+ if (t->vtime_snap_whence == VTIME_SYS && t->flags & PF_VCPU)
gtime += vtime_delta(t);
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seqcount, seq));
return gtime;
}
@@ -821,7 +833,7 @@ fetch_task_cputime(struct task_struct *t,
*udelta = 0;
*sdelta = 0;
- seq = read_seqbegin(&t->vtime_seqlock);
+ seq = read_seqcount_begin(&t->vtime_seqcount);
if (u_dst)
*u_dst = *u_src;
@@ -829,7 +841,7 @@ fetch_task_cputime(struct task_struct *t,
*s_dst = *s_src;
/* Task is sleeping, nothing to add */
- if (t->vtime_snap_whence == VTIME_SLEEPING ||
+ if (t->vtime_snap_whence == VTIME_INACTIVE ||
is_idle_task(t))
continue;
@@ -845,7 +857,7 @@ fetch_task_cputime(struct task_struct *t,
if (t->vtime_snap_whence == VTIME_SYS)
*sdelta = delta;
}
- } while (read_seqretry(&t->vtime_seqlock, seq));
+ } while (read_seqcount_retry(&t->vtime_seqcount, seq));
}
@@ -853,6 +865,14 @@ void task_cputime(struct task_struct *t, cputime_t *utime, cputime_t *stime)
{
cputime_t udelta, sdelta;
+ if (!vtime_accounting_enabled()) {
+ if (utime)
+ *utime = t->utime;
+ if (stime)
+ *stime = t->stime;
+ return;
+ }
+
fetch_task_cputime(t, utime, stime, &t->utime,
&t->stime, &udelta, &sdelta);
if (utime)
@@ -866,6 +886,14 @@ void task_cputime_scaled(struct task_struct *t,
{
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)