[PATCH] mutex subsystem, more debugging code

more mutex debugging: check for held locks during memory freeing,
task exit, enable sysrq printouts, etc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@infradead.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 145275ebdd7e..5765f672e853 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -153,6 +153,21 @@ static struct sysrq_key_op sysrq_mountro_op = {
 
 /* END SYNC SYSRQ HANDLERS BLOCK */
 
+#ifdef CONFIG_DEBUG_MUTEXES
+
+static void
+sysrq_handle_showlocks(int key, struct pt_regs *pt_regs, struct tty_struct *tty)
+{
+        mutex_debug_show_all_locks();
+}
+
+static struct sysrq_key_op sysrq_showlocks_op = {
+        .handler        = sysrq_handle_showlocks,
+        .help_msg       = "show-all-locks(D)",
+        .action_msg     = "Show Locks Held",
+};
+
+#endif
 
 /* SHOW SYSRQ HANDLERS BLOCK */
 
@@ -294,7 +309,11 @@ static struct sysrq_key_op *sysrq_key_table[SYSRQ_KEY_TABLE_LENGTH] = {
 #else
 /* c */ NULL,
 #endif
+#ifdef CONFIG_DEBUG_MUTEXES
+/* d */ &sysrq_showlocks_op,
+#else
 /* d */ NULL,
+#endif
 /* e */ &sysrq_term_op,
 /* f */ &sysrq_moom_op,
 /* g */ NULL,