ftrace: sysrq-z to dump the buffers
Impact: add SysRq-z support to dump trace buffers
Allows one to force an ftrace dump from sysrq
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index ce0d9da..94966ed 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -274,6 +274,22 @@
.enable_mask = SYSRQ_ENABLE_DUMP,
};
+#ifdef CONFIG_TRACING
+#include <linux/ftrace.h>
+
+static void sysrq_ftrace_dump(int key, struct tty_struct *tty)
+{
+ ftrace_dump();
+}
+static struct sysrq_key_op sysrq_ftrace_dump_op = {
+ .handler = sysrq_ftrace_dump,
+ .help_msg = "dumpZ-ftrace-buffer",
+ .action_msg = "Dump ftrace buffer",
+ .enable_mask = SYSRQ_ENABLE_DUMP,
+};
+#else
+#define sysrq_ftrace_dump_op (*(struct sysrq_key_op *)0)
+#endif
static void sysrq_handle_showmem(int key, struct tty_struct *tty)
{
@@ -406,7 +422,7 @@
NULL, /* x */
/* y: May be registered on sparc64 for global register dump */
NULL, /* y */
- NULL /* z */
+ &sysrq_ftrace_dump_op, /* z */
};
/* key2index calculation, -1 on invalid index */