[PATCH v3 16/17] Fix schedstat handling

Steven Rostedt
2007-11-17T06:30:29Z

[-- Attachment #1: rt-balance-wakup-fix-schedstat.patch --]
[-- Type: text/plain, Size: 4736 bytes --]

Gregory Haskins RT balancing broke sched domains.
This is a fix to allow it to still work.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>

---
include/linux/sched.h | 3 ++-
kernel/sched.c | 17 ++++++++++++++---
kernel/sched_fair.c | 19 ++++++++++++++-----
kernel/sched_idletask.c | 3 ++-
kernel/sched_rt.c | 3 ++-
5 files changed, 34 insertions(+), 11 deletions(-)

Index: linux-compile.git/kernel/sched.c
===================================================================
--- linux-compile.git.orig/kernel/sched.c 2007-11-17 00:15:57.000000000 -0500
+++ linux-compile.git/kernel/sched.c 2007-11-17 00:15:57.000000000 -0500
@@ -1453,6 +1453,7 @@ static int try_to_wake_up(struct task_st
unsigned long flags;
long old_state;
struct rq *rq;
+ struct sched_domain *this_sd = NULL;
#ifdef CONFIG_SMP
int new_cpu;
#endif
@@ -1476,10 +1477,20 @@ static int try_to_wake_up(struct task_st
schedstat_inc(rq, ttwu_count);
if (cpu == this_cpu)
schedstat_inc(rq, ttwu_local);
- else
- schedstat_inc(rq->sd, ttwu_wake_remote);
+ else {
+#ifdef CONFIG_SCHEDSTATS
+ struct sched_domain *sd;
+ for_each_domain(this_cpu, sd) {
+ if (cpu_isset(cpu, sd->span)) {
+ schedstat_inc(sd, ttwu_wake_remote);
+ this_sd = sd;
+ break;
+ }
+ }
+#endif /* CONFIG_SCHEDSTATES */
+ }

- new_cpu = p->sched_class->select_task_rq(p, sync);
+ new_cpu = p->sched_class->select_task_rq(p, this_sd, sync);

if (new_cpu != cpu) {
set_task_cpu(p, new_cpu);
Index: linux-compile.git/include/linux/sched.h
===================================================================
--- linux-compile.git.orig/include/linux/sched.h 2007-11-17 00:15:57.000000000 -0500
+++ linux-compile.git/include/linux/sched.h 2007-11-17 00:15:57.000000000 -0500
@@ -823,7 +823,8 @@ struct sched_class {
void (*enqueue_task) (struct rq *rq, struct task_struct *p, int wakeup);
void (*dequeue_task) (struct rq *rq, struct task_struct *p, int sleep);
void (*yield_task) (struct rq *rq);
- int (*select_task_rq)(struct task_struct *p, int sync);
+ int (*select_task_rq)(struct task_struct *p,
+ struct sched_domain *sd, int sync);

void (*check_preempt_curr) (struct rq *rq, struct task_struct *p);

Index: linux-compile.git/kernel/sched_fair.c
===================================================================
--- linux-compile.git.orig/kernel/sched_fair.c 2007-11-17 00:15:57.000000000 -0500
+++ linux-compile.git/kernel/sched_fair.c 2007-11-17 00:43:44.000000000 -0500
@@ -611,11 +611,12 @@ static inline int wake_idle(int cpu, str
#endif

#ifdef CONFIG_SMP
-static int select_task_rq_fair(struct task_struct *p, int sync)
+static int select_task_rq_fair(struct task_struct *p,
+ struct sched_domain *this_sd, int sync)
{
int cpu, this_cpu;
struct rq *rq;
- struct sched_domain *sd, *this_sd = NULL;
+ struct sched_domain *sd;
int new_cpu;

cpu = task_cpu(p);
@@ -623,15 +624,23 @@ static int select_task_rq_fair(struct ta
this_cpu = smp_processor_id();
new_cpu = cpu;

+ if (cpu == this_cpu || unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
+ goto out_set_cpu;
+
+#ifndef CONFIG_SCHEDSTATS
+ /*
+ * If SCHEDSTATS is configured, then this_sd would
+ * have already been determined.
+ */
for_each_domain(this_cpu, sd) {
if (cpu_isset(cpu, sd->span)) {
this_sd = sd;
break;
}
}
-
- if (unlikely(!cpu_isset(this_cpu, p->cpus_allowed)))
- goto out_set_cpu;
+#else
+ (void)sd; /* unused */
+#endif /* CONFIG_SCHEDSTATS */

/*
* Check for affine wakeup and passive balancing possibilities.
Index: linux-compile.git/kernel/sched_idletask.c
===================================================================
--- linux-compile.git.orig/kernel/sched_idletask.c 2007-11-17 00:15:57.000000000 -0500
+++ linux-compile.git/kernel/sched_idletask.c 2007-11-17 00:15:57.000000000 -0500
@@ -6,7 +6,8 @@
*/

#ifdef CONFIG_SMP
-static int select_task_rq_idle(struct task_struct *p, int sync)
+static int select_task_rq_idle(struct task_struct *p,
+ struct sched_domain *sd, int sync)
{
return task_cpu(p); /* IDLE tasks as never migrated */
}
Index: linux-compile.git/kernel/sched_rt.c
===================================================================
--- linux-compile.git.orig/kernel/sched_rt.c 2007-11-17 00:15:57.000000000 -0500
+++ linux-compile.git/kernel/sched_rt.c 2007-11-17 00:44:31.000000000 -0500
@@ -46,7 +46,8 @@ static void update_rt_migration(struct r

static int find_lowest_rq(struct task_struct *task);

-static int select_task_rq_rt(struct task_struct *p, int sync)
+static int select_task_rq_rt(struct task_struct *p,
+ struct sched_domain *sd, int sync)
{
struct rq *rq = task_rq(p);

--