[GIT PULL] scheduler fixes

Ingo Molnar
2014-11-20T07:57:14Z

Linus,

Please pull the latest sched-urgent-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-for-linus

# HEAD: 6e998916dfe327e785e7c2447959b2c1a3ea4930 sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency

Misc fixes: two NUMA fixes, two cputime fixes and an RCU/lockdep
fix.

Thanks,

Ingo

------------------>
Andrey Ryabinin (1):
sched/numa: Fix out of bounds read in sched_init_numa()

Kirill Tkhai (1):
sched: Remove lockdep check in sched_move_task()

Peter Zijlstra (2):
sched/numa: Avoid selecting oneself as swap target
sched/cputime: Fix cpu_timer_sample_group() double accounting

Stanislaw Gruszka (1):
sched/cputime: Fix clock_nanosleep()/clock_gettime() inconsistency

include/linux/kernel_stat.h | 5 ----
kernel/sched/core.c | 63 ++++++++++++++----------------------------
kernel/sched/deadline.c | 2 ++
kernel/sched/fair.c | 14 ++++++++++
kernel/sched/rt.c | 2 ++
kernel/sched/sched.h | 2 ++
kernel/time/posix-cpu-timers.c | 2 +-
7 files changed, 42 insertions(+), 48 deletions(-)

diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h
index 8422b4ed6882..b9376cd5a187 100644
--- a/include/linux/kernel_stat.h
+++ b/include/linux/kernel_stat.h
@@ -77,11 +77,6 @@ static inline unsigned int kstat_cpu_irqs_sum(unsigned int cpu)
return kstat_cpu(cpu).irqs_sum;
}

-/*
- * Lock/unlock the current runqueue - to extract task statistics:
- */
-extern unsigned long long task_delta_exec(struct task_struct *);
-
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_steal_time(cputime_t);
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 240157c13ddc..24beb9bb4c3e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2475,44 +2475,6 @@ EXPORT_PER_CPU_SYMBOL(kstat);
EXPORT_PER_CPU_SYMBOL(kernel_cpustat);

/*
- * Return any ns on the sched_clock that have not yet been accounted in
- * @p in case that task is currently running.
- *
- * Called with task_rq_lock() held on @rq.
- */
-static u64 do_task_delta_exec(struct task_struct *p, struct rq *rq)
-{
- u64 ns = 0;
-
- /*
- * Must be ->curr _and_ ->on_rq. If dequeued, we would
- * project cycles that may never be accounted to this
- * thread, breaking clock_gettime().
- */
- if (task_current(rq, p) && task_on_rq_queued(p)) {
- update_rq_clock(rq);
- ns = rq_clock_task(rq) - p->se.exec_start;
- if ((s64)ns < 0)
- ns = 0;
- }
-
- return ns;
-}
-
-unsigned long long task_delta_exec(struct task_struct *p)
-{
- unsigned long flags;
- struct rq *rq;
- u64 ns = 0;
-
- rq = task_rq_lock(p, &flags);
- ns = do_task_delta_exec(p, rq);
- task_rq_unlock(rq, p, &flags);
-
- return ns;
-}
-
-/*
* Return accounted runtime for the task.
* In case the task is currently running, return the runtime plus current's
* pending runtime that have not been accounted yet.
@@ -2521,7 +2483,7 @@ unsigned long long task_sched_runtime(struct task_struct *p)
{
unsigned long flags;
struct rq *rq;
- u64 ns = 0;
+ u64 ns;

#if defined(CONFIG_64BIT) && defined(CONFIG_SMP)
/*
@@ -2540,7 +2502,16 @@ unsigned long long task_sched_runtime(struct task_struct *p)
#endif

rq = task_rq_lock(p, &flags);
- ns = p->se.sum_exec_runtime + do_task_delta_exec(p, rq);
+ /*
+ * Must be ->curr _and_ ->on_rq. If dequeued, we would
+ * project cycles that may never be accounted to this
+ * thread, breaking clock_gettime().
+ */
+ if (task_current(rq, p) && task_on_rq_queued(p)) {
+ update_rq_clock(rq);
+ p->sched_class->update_curr(rq);
+ }
+ ns = p->se.sum_exec_runtime;
task_rq_unlock(rq, p, &flags);

return ns;
@@ -6368,6 +6339,10 @@ static void sched_init_numa(void)
if (!sched_debug())
break;
}
+
+ if (!level)
+ return;
+
/*
* 'level' contains the number of unique distances, excluding the
* identity distance node_distance(i,i).
@@ -7444,8 +7419,12 @@ void sched_move_task(struct task_struct *tsk)
if (unlikely(running))
put_prev_task(rq, tsk);

- tg = container_of(task_css_check(tsk, cpu_cgrp_id,
- lockdep_is_held(&tsk->sighand->siglock)),
+ /*
+ * All callers are synchronized by task_rq_lock(); we do not use RCU
+ * which is pointless here. Thus, we pass "true" to task_css_check()
+ * to prevent lockdep warnings.
+ */
+ tg = container_of(task_css_check(tsk, cpu_cgrp_id, true),
struct task_group, css);
tg = autogroup_task_group(tsk, tg);
tsk->sched_task_group = tg;
diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 5285332392d5..28fa9d9e9201 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1701,4 +1701,6 @@ const struct sched_class dl_sched_class = {
.prio_changed = prio_changed_dl,
.switched_from = switched_from_dl,
.switched_to = switched_to_dl,
+
+ .update_curr = update_curr_dl,
};
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 34baa60f8a7b..ef2b104b254c 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -726,6 +726,11 @@ static void update_curr(struct cfs_rq *cfs_rq)
account_cfs_rq_runtime(cfs_rq, delta_exec);
}

+static void update_curr_fair(struct rq *rq)
+{
+ update_curr(cfs_rq_of(&rq->curr->se));
+}
+
static inline void
update_stats_wait_start(struct cfs_rq *cfs_rq, struct sched_entity *se)
{
@@ -1180,6 +1185,13 @@ static void task_numa_compare(struct task_numa_env *env,
raw_spin_unlock_irq(&dst_rq->lock);

/*
+ * Because we have preemption enabled we can get migrated around and
+ * end try selecting ourselves (current == env->p) as a swap candidate.
+ */
+ if (cur == env->p)
+ goto unlock;
+
+ /*
* "imp" is the fault differential for the source task between the
* source and destination node. Calculate the total differential for
* the source task and potential destination task. The more negative
@@ -7949,6 +7961,8 @@ const struct sched_class fair_sched_class = {

.get_rr_interval = get_rr_interval_fair,

+ .update_curr = update_curr_fair,
+
#ifdef CONFIG_FAIR_GROUP_SCHED
.task_move_group = task_move_group_fair,
#endif
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index d024e6ce30ba..20bca398084a 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -2128,6 +2128,8 @@ const struct sched_class rt_sched_class = {

.prio_changed = prio_changed_rt,
.switched_to = switched_to_rt,
+
+ .update_curr = update_curr_rt,
};

#ifdef CONFIG_SCHED_DEBUG
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index 24156c8434d1..2df8ef067cc5 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -1135,6 +1135,8 @@ struct sched_class {
unsigned int (*get_rr_interval) (struct rq *rq,
struct task_struct *task);

+ void (*update_curr) (struct rq *rq);
+
#ifdef CONFIG_FAIR_GROUP_SCHED
void (*task_move_group) (struct task_struct *p, int on_rq);
#endif
diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index 492b986195d5..a16b67859e2a 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -553,7 +553,7 @@ static int cpu_timer_sample_group(const clockid_t which_clock,
*sample = cputime_to_expires(cputime.utime);
break;
case CPUCLOCK_SCHED:
- *sample = cputime.sum_exec_runtime + task_delta_exec(p);
+ *sample = cputime.sum_exec_runtime;
break;
}
return 0;