[GIT PULL] scheduler fixes

[Ingo Molnar]

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: 4698f88c06b893f2acc0b443004a53bf490fde7c sched/debug: Fix 
'schedstats=enable' cmdline option

Two scheduler debugging fixes.

 Thanks,

        Ingo

------------------>
Josh Poimboeuf (2):
      sched/debug: Fix /proc/sched_debug regression
      sched/debug: Fix 'schedstats=enable' cmdline option


 kernel/sched/core.c  | 26 +++++++++++++++++++++-----
 kernel/sched/debug.c | 15 ++++-----------
 kernel/sched/stats.h |  3 +++
 3 files changed, 28 insertions(+), 16 deletions(-)

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 7f2cae4620c7..385c947482e1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -2253,9 +2253,11 @@ int sysctl_numa_balancing(struct ctl_table *table, int 
write,
 #endif
 #endif
 
+#ifdef CONFIG_SCHEDSTATS
+
 DEFINE_STATIC_KEY_FALSE(sched_schedstats);
+static bool __initdata __sched_schedstats = false;
 
-#ifdef CONFIG_SCHEDSTATS
 static void set_schedstats(bool enabled)
 {
        if (enabled)
@@ -2278,11 +2280,16 @@ static int __init setup_schedstats(char *str)
        if (!str)
                goto out;
 
+       /*
+        * This code is called before jump labels have been set up, so we can't
+        * change the static branch directly just yet.  Instead set a temporary
+        * variable so init_schedstats() can do it later.
+        */
        if (!strcmp(str, "enable")) {
-               set_schedstats(true);
+               __sched_schedstats = true;
                ret = 1;
        } else if (!strcmp(str, "disable")) {
-               set_schedstats(false);
+               __sched_schedstats = false;
                ret = 1;
        }
 out:
@@ -2293,6 +2300,11 @@ static int __init setup_schedstats(char *str)
 }
 __setup("schedstats=", setup_schedstats);
 
+static void __init init_schedstats(void)
+{
+       set_schedstats(__sched_schedstats);
+}
+
 #ifdef CONFIG_PROC_SYSCTL
 int sysctl_schedstats(struct ctl_table *table, int write,
                         void __user *buffer, size_t *lenp, loff_t *ppos)
@@ -2313,8 +2325,10 @@ int sysctl_schedstats(struct ctl_table *table, int write,
                set_schedstats(state);
        return err;
 }
-#endif
-#endif
+#endif /* CONFIG_PROC_SYSCTL */
+#else  /* !CONFIG_SCHEDSTATS */
+static inline void init_schedstats(void) {}
+#endif /* CONFIG_SCHEDSTATS */
 
 /*
  * fork()/clone()-time setup:
@@ -7487,6 +7501,8 @@ void __init sched_init(void)
 #endif
        init_sched_fair_class();
 
+       init_schedstats();
+
        scheduler_running = 1;
 }
 
diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c
index cf905f655ba1..0368c393a336 100644
--- a/kernel/sched/debug.c
+++ b/kernel/sched/debug.c
@@ -427,19 +427,12 @@ print_task(struct seq_file *m, struct rq *rq, struct 
task_struct *p)
                SPLIT_NS(p->se.vruntime),
                (long long)(p->nvcsw + p->nivcsw),
                p->prio);
-#ifdef CONFIG_SCHEDSTATS
-       if (schedstat_enabled()) {
-               SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
-                       SPLIT_NS(p->se.statistics.wait_sum),
-                       SPLIT_NS(p->se.sum_exec_runtime),
-                       SPLIT_NS(p->se.statistics.sum_sleep_runtime));
-       }
-#else
+
        SEQ_printf(m, "%9Ld.%06ld %9Ld.%06ld %9Ld.%06ld",
-               0LL, 0L,
+               SPLIT_NS(schedstat_val(p, se.statistics.wait_sum)),
                SPLIT_NS(p->se.sum_exec_runtime),
-               0LL, 0L);
-#endif
+               SPLIT_NS(schedstat_val(p, se.statistics.sum_sleep_runtime)));
+
 #ifdef CONFIG_NUMA_BALANCING
        SEQ_printf(m, " %d %d", task_node(p), task_numa_group_id(p));
 #endif
diff --git a/kernel/sched/stats.h b/kernel/sched/stats.h
index 70b3b6a20fb0..78955cbea31c 100644
--- a/kernel/sched/stats.h
+++ b/kernel/sched/stats.h
@@ -33,6 +33,8 @@ rq_sched_info_dequeued(struct rq *rq, unsigned long long 
delta)
 # define schedstat_inc(rq, field)      do { if (schedstat_enabled()) { 
(rq)->field++; } } while (0)
 # define schedstat_add(rq, field, amt) do { if (schedstat_enabled()) { 
(rq)->field += (amt); } } while (0)
 # define schedstat_set(var, val)       do { if (schedstat_enabled()) { var = 
(val); } } while (0)
+# define schedstat_val(rq, field)      ((schedstat_enabled()) ? (rq)->field : 
0)
+
 #else /* !CONFIG_SCHEDSTATS */
 static inline void
 rq_sched_info_arrive(struct rq *rq, unsigned long long delta)
@@ -47,6 +49,7 @@ rq_sched_info_depart(struct rq *rq, unsigned long long delta)
 # define schedstat_inc(rq, field)      do { } while (0)
 # define schedstat_add(rq, field, amt) do { } while (0)
 # define schedstat_set(var, val)       do { } while (0)
+# define schedstat_val(rq, field)      0
 #endif
 
 #ifdef CONFIG_SCHED_INFO