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authorIngo Molnar <mingo@elte.hu>2006-12-06 20:35:59 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-07 08:39:32 -0800
commite59e2ae2c29700117a54e85c106017c24837119f (patch)
treed746e90d2d79fa8458d021d3572bc55ebdc3aca3
parent875d95ec9eb69ffb334116fb44d04d9a64dcbfbb (diff)
[PATCH] SysRq-X: show blocked tasks
Add SysRq-X support: show blocked (TASK_UNINTERRUPTIBLE) tasks only. Useful for debugging IO stalls. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--drivers/char/sysrq.c14
-rw-r--r--include/linux/sched.h11
-rw-r--r--kernel/sched.c11
3 files changed, 31 insertions, 5 deletions
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index c64f5bcff947..05810c8d20bc 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -182,6 +182,18 @@ static struct sysrq_key_op sysrq_showstate_op = {
.enable_mask = SYSRQ_ENABLE_DUMP,
};
+static void sysrq_handle_showstate_blocked(int key, struct tty_struct *tty)
+{
+ show_state_filter(TASK_UNINTERRUPTIBLE);
+}
+static struct sysrq_key_op sysrq_showstate_blocked_op = {
+ .handler = sysrq_handle_showstate_blocked,
+ .help_msg = "showBlockedTasks",
+ .action_msg = "Show Blocked State",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+
+
static void sysrq_handle_showmem(int key, struct tty_struct *tty)
{
show_mem();
@@ -304,7 +316,7 @@ static struct sysrq_key_op *sysrq_key_table[36] = {
/* May be assigned at init time by SMP VOYAGER */
NULL, /* v */
NULL, /* w */
- NULL, /* x */
+ &sysrq_showstate_blocked_op, /* x */
NULL, /* y */
NULL /* z */
};
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 837a012f573c..0a90cefb0b0d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -194,7 +194,16 @@ extern void init_idle(struct task_struct *idle, int cpu);
extern cpumask_t nohz_cpu_mask;
-extern void show_state(void);
+/*
+ * Only dump TASK_* tasks. (-1 for all tasks)
+ */
+extern void show_state_filter(unsigned long state_filter);
+
+static inline void show_state(void)
+{
+ show_state_filter(-1);
+}
+
extern void show_regs(struct pt_regs *);
/*
diff --git a/kernel/sched.c b/kernel/sched.c
index 12fdbef1d9bf..1848e280504d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -4804,7 +4804,7 @@ static void show_task(struct task_struct *p)
show_stack(p, NULL);
}
-void show_state(void)
+void show_state_filter(unsigned long state_filter)
{
struct task_struct *g, *p;
@@ -4824,11 +4824,16 @@ void show_state(void)
* console might take alot of time:
*/
touch_nmi_watchdog();
- show_task(p);
+ if (p->state & state_filter)
+ show_task(p);
} while_each_thread(g, p);
read_unlock(&tasklist_lock);
- debug_show_all_locks();
+ /*
+ * Only show locks if all tasks are dumped:
+ */
+ if (state_filter == -1)
+ debug_show_all_locks();
}
/**