Commit f6d13daa authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "A couple of regression fixes mostly hitting virtualized setups, but
  also some bare metal systems"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/x86/tsc: Initialize multiplier to 0
  sched/clock: Fixup early initialization
  sched/preempt/x86: Fix voluntary preempt for x86
  Revert "sched: Fix sleep time double accounting in enqueue entity"
parents d4a63a83 5e3c1afd
...@@ -180,7 +180,7 @@ static void cyc2ns_write_end(int cpu, struct cyc2ns_data *data) ...@@ -180,7 +180,7 @@ static void cyc2ns_write_end(int cpu, struct cyc2ns_data *data)
static void cyc2ns_data_init(struct cyc2ns_data *data) static void cyc2ns_data_init(struct cyc2ns_data *data)
{ {
data->cyc2ns_mul = 1U << CYC2NS_SCALE_FACTOR; data->cyc2ns_mul = 0;
data->cyc2ns_shift = CYC2NS_SCALE_FACTOR; data->cyc2ns_shift = CYC2NS_SCALE_FACTOR;
data->cyc2ns_offset = 0; data->cyc2ns_offset = 0;
data->__count = 0; data->__count = 0;
......
...@@ -134,7 +134,6 @@ do { \ ...@@ -134,7 +134,6 @@ do { \
#undef preempt_check_resched #undef preempt_check_resched
#endif #endif
#ifdef CONFIG_PREEMPT
#define preempt_set_need_resched() \ #define preempt_set_need_resched() \
do { \ do { \
set_preempt_need_resched(); \ set_preempt_need_resched(); \
...@@ -144,10 +143,6 @@ do { \ ...@@ -144,10 +143,6 @@ do { \
if (tif_need_resched()) \ if (tif_need_resched()) \
set_preempt_need_resched(); \ set_preempt_need_resched(); \
} while (0) } while (0)
#else
#define preempt_set_need_resched() do { } while (0)
#define preempt_fold_need_resched() do { } while (0)
#endif
#ifdef CONFIG_PREEMPT_NOTIFIERS #ifdef CONFIG_PREEMPT_NOTIFIERS
......
...@@ -77,35 +77,50 @@ __read_mostly int sched_clock_running; ...@@ -77,35 +77,50 @@ __read_mostly int sched_clock_running;
#ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK #ifdef CONFIG_HAVE_UNSTABLE_SCHED_CLOCK
static struct static_key __sched_clock_stable = STATIC_KEY_INIT; static struct static_key __sched_clock_stable = STATIC_KEY_INIT;
static int __sched_clock_stable_early;
int sched_clock_stable(void) int sched_clock_stable(void)
{ {
if (static_key_false(&__sched_clock_stable)) return static_key_false(&__sched_clock_stable);
return false;
return true;
} }
void set_sched_clock_stable(void) static void __set_sched_clock_stable(void)
{ {
if (!sched_clock_stable()) if (!sched_clock_stable())
static_key_slow_dec(&__sched_clock_stable); static_key_slow_inc(&__sched_clock_stable);
}
void set_sched_clock_stable(void)
{
__sched_clock_stable_early = 1;
smp_mb(); /* matches sched_clock_init() */
if (!sched_clock_running)
return;
__set_sched_clock_stable();
} }
static void __clear_sched_clock_stable(struct work_struct *work) static void __clear_sched_clock_stable(struct work_struct *work)
{ {
/* XXX worry about clock continuity */ /* XXX worry about clock continuity */
if (sched_clock_stable()) if (sched_clock_stable())
static_key_slow_inc(&__sched_clock_stable); static_key_slow_dec(&__sched_clock_stable);
} }
static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable); static DECLARE_WORK(sched_clock_work, __clear_sched_clock_stable);
void clear_sched_clock_stable(void) void clear_sched_clock_stable(void)
{ {
if (keventd_up()) __sched_clock_stable_early = 0;
smp_mb(); /* matches sched_clock_init() */
if (!sched_clock_running)
return;
schedule_work(&sched_clock_work); schedule_work(&sched_clock_work);
else
__clear_sched_clock_stable(&sched_clock_work);
} }
struct sched_clock_data { struct sched_clock_data {
...@@ -140,6 +155,20 @@ void sched_clock_init(void) ...@@ -140,6 +155,20 @@ void sched_clock_init(void)
} }
sched_clock_running = 1; sched_clock_running = 1;
/*
* Ensure that it is impossible to not do a static_key update.
*
* Either {set,clear}_sched_clock_stable() must see sched_clock_running
* and do the update, or we must see their __sched_clock_stable_early
* and do the update, or both.
*/
smp_mb(); /* matches {set,clear}_sched_clock_stable() */
if (__sched_clock_stable_early)
__set_sched_clock_stable();
else
__clear_sched_clock_stable(NULL);
} }
/* /*
...@@ -340,7 +369,7 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event); ...@@ -340,7 +369,7 @@ EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
*/ */
u64 cpu_clock(int cpu) u64 cpu_clock(int cpu)
{ {
if (static_key_false(&__sched_clock_stable)) if (!sched_clock_stable())
return sched_clock_cpu(cpu); return sched_clock_cpu(cpu);
return sched_clock(); return sched_clock();
...@@ -355,7 +384,7 @@ u64 cpu_clock(int cpu) ...@@ -355,7 +384,7 @@ u64 cpu_clock(int cpu)
*/ */
u64 local_clock(void) u64 local_clock(void)
{ {
if (static_key_false(&__sched_clock_stable)) if (!sched_clock_stable())
return sched_clock_cpu(raw_smp_processor_id()); return sched_clock_cpu(raw_smp_processor_id());
return sched_clock(); return sched_clock();
......
...@@ -2360,13 +2360,7 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq, ...@@ -2360,13 +2360,7 @@ static inline void enqueue_entity_load_avg(struct cfs_rq *cfs_rq,
} }
wakeup = 0; wakeup = 0;
} else { } else {
/* __synchronize_entity_decay(se);
* Task re-woke on same cpu (or else migrate_task_rq_fair()
* would have made count negative); we must be careful to avoid
* double-accounting blocked time after synchronizing decays.
*/
se->avg.last_runnable_update += __synchronize_entity_decay(se)
<< 20;
} }
/* migrated tasks did not contribute to our blocked load */ /* migrated tasks did not contribute to our blocked load */
......
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