sched: Reinstate group names in /proc/sched_debug

Displaying of group names in /proc/sched_debug was dropped in autogroup
patches. Add group names while displaying cfs_rq and tasks information.

Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20110111101153.GE4772@in.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 35 insertions, 0 deletions

diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 1dfae3d014b5..4d36f3726da7 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -16,6 +16,8 @@
 #include <linux/kallsyms.h>
 #include <linux/utsname.h>
 
+static DEFINE_SPINLOCK(sched_debug_lock);
+
 /*
  * This allows printing both to /proc/sched_debug and
  * to the console
@@ -86,6 +88,23 @@ static void print_cfs_group_stats(struct seq_file *m, int cpu, struct task_group
 }
 #endif
 
+#ifdef CONFIG_CGROUP_SCHED
+static char group_path[PATH_MAX];
+
+static char *task_group_path(struct task_group *tg)
+{
+        /*
+         * May be NULL if the underlying cgroup isn't fully-created yet
+         */
+        if (!tg->css.cgroup) {
+                group_path[0] = '\0';
+                return group_path;
+        }
+        cgroup_path(tg->css.cgroup, group_path, PATH_MAX);
+        return group_path;
+}
+#endif
+
 static void
 print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
 {
@@ -108,6 +127,9 @@ print_task(struct seq_file *m, struct rq *rq, struct task_struct *p)
         SEQ_printf(m, "%15Ld %15Ld %15Ld.%06ld %15Ld.%06ld %15Ld.%06ld",
                 0LL, 0LL, 0LL, 0L, 0LL, 0L, 0LL, 0L);
 #endif
+#ifdef CONFIG_CGROUP_SCHED
+        SEQ_printf(m, " %s", task_group_path(task_group(p)));
+#endif
 
         SEQ_printf(m, "\n");
 }
@@ -144,7 +166,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
         struct sched_entity *last;
         unsigned long flags;
 
+#ifdef CONFIG_FAIR_GROUP_SCHED
+        SEQ_printf(m, "\ncfs_rq[%d]:%s\n", cpu, task_group_path(cfs_rq->tg));
+#else
         SEQ_printf(m, "\ncfs_rq[%d]:\n", cpu);
+#endif
         SEQ_printf(m, "  .%-30s: %Ld.%06ld\n", "exec_clock",
                         SPLIT_NS(cfs_rq->exec_clock));
 
@@ -191,7 +217,11 @@ void print_cfs_rq(struct seq_file *m, int cpu, struct cfs_rq *cfs_rq)
 
 void print_rt_rq(struct seq_file *m, int cpu, struct rt_rq *rt_rq)
 {
+#ifdef CONFIG_RT_GROUP_SCHED
+        SEQ_printf(m, "\nrt_rq[%d]:%s\n", cpu, task_group_path(rt_rq->tg));
+#else
         SEQ_printf(m, "\nrt_rq[%d]:\n", cpu);
+#endif
 
 #define P(x) \
         SEQ_printf(m, "  .%-30s: %Ld\n", #x, (long long)(rt_rq->x))
@@ -212,6 +242,7 @@ extern __read_mostly int sched_clock_running;
 static void print_cpu(struct seq_file *m, int cpu)
 {
         struct rq *rq = cpu_rq(cpu);
+        unsigned long flags;
 
 #ifdef CONFIG_X86
         {
@@ -266,10 +297,14 @@ static void print_cpu(struct seq_file *m, int cpu)
 
 #undef P
 #endif
+        spin_lock_irqsave(&sched_debug_lock, flags);
         print_cfs_stats(m, cpu);
         print_rt_stats(m, cpu);
 
+        rcu_read_lock();
         print_rq(m, rq, cpu);
+        rcu_read_unlock();
+        spin_unlock_irqrestore(&sched_debug_lock, flags);
 }
 
 static const char *sched_tunable_scaling_names[] = {