Err... sorry for the broken patch. The patch below on top of the
previous one should address this issue (ugly, but should be ok for
debugging).
'tasklist_lock' shouldn't cause a double lock, I guess.
Sorry for rather 'blind' attempts. If no, then I'll
prepare/test/take-a-closer-look at it later today when I'm at home.
TIA,
------ kernel/sched_debug-prev.c 2008-05-14 14:53:28.000000000 +0200
+++ kernel/sched_debug.c 2008-05-14 14:58:12.000000000 +0200
@@ -125,6 +125,7 @@ void print_cfs_rq(struct seq_file *m, in
char path[128] = "";
struct cgroup *cgroup = NULL;
struct task_group *tg = cfs_rq->tg;
+ int was_locked;
if (tg)
cgroup = tg->css.cgroup;
@@ -138,7 +139,11 @@ void print_cfs_rq(struct seq_file *m, in
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "exec_clock",
SPLIT_NS(cfs_rq->exec_clock));
- spin_lock_irqsave(&rq->lock, flags);
+ was_locked = spin_is_locked(&rq->lock);
+
+ if (!was_locked)
+ spin_lock_irqsave(&rq->lock, flags);
+
if (cfs_rq->rb_leftmost)
MIN_vruntime = (__pick_next_entity(cfs_rq))->vruntime;
last = __pick_last_entity(cfs_rq);
@@ -146,7 +151,10 @@ void print_cfs_rq(struct seq_file *m, in
max_vruntime = last->vruntime;
min_vruntime = rq->cfs.min_vruntime;
rq0_min_vruntime = per_cpu(runqueues, 0).cfs.min_vruntime;
- spin_unlock_irqrestore(&rq->lock, flags);
+
+ if (!was_locked)
+ spin_unlock_irqrestore(&rq->lock, flags);
+
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "MIN_vruntime",
SPLIT_NS(MIN_vruntime));
SEQ_printf(m, " .%-30s: %Ld.%06ld\n", "min_vruntime",
---
--
Best regards,
Dmitry Adamushko
