This adds two new lock contention tracepoints like below:
* lock:contention_begin
* lock:contention_end
The lock:contention_begin takes a flags argument to classify locks. I
found it useful to identify what kind of locks it's tracing like if
it's spinning or sleeping, reader-writer lock, real-time, and per-cpu.
Move tracepoint definitions into mutex.c so that we can use them
without lockdep.
Tested-by: Hyeonggon Yoo <42.hyeyoo@xxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
include/trace/events/lock.h | 61 +++++++++++++++++++++++++++++++++++--
kernel/locking/lockdep.c | 1 -
kernel/locking/mutex.c | 3 ++
3 files changed, 61 insertions(+), 4 deletions(-)
diff --git a/include/trace/events/lock.h b/include/trace/events/lock.h
index d7512129a324..b9b6e3edd518 100644
--- a/include/trace/events/lock.h
+++ b/include/trace/events/lock.h
@@ -5,11 +5,21 @@
#if !defined(_TRACE_LOCK_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_LOCK_H
-#include <linux/lockdep.h>
+#include <linux/sched.h>
#include <linux/tracepoint.h>
+/* flags for lock:contention_begin */
+#define LCB_F_SPIN (1U << 0)
+#define LCB_F_READ (1U << 1)
+#define LCB_F_WRITE (1U << 2)
+#define LCB_F_RT (1U << 3)
+#define LCB_F_PERCPU (1U << 4)
+
+
#ifdef CONFIG_LOCKDEP
+#include <linux/lockdep.h>
+
TRACE_EVENT(lock_acquire,
TP_PROTO(struct lockdep_map *lock, unsigned int subclass,
@@ -78,8 +88,53 @@ DEFINE_EVENT(lock, lock_acquired,
TP_ARGS(lock, ip)
);
-#endif
-#endif
+#endif /* CONFIG_LOCK_STAT */
+#endif /* CONFIG_LOCKDEP */
+
+TRACE_EVENT(contention_begin,
+
+ TP_PROTO(void *lock, unsigned int flags),
+
+ TP_ARGS(lock, flags),
+
+ TP_STRUCT__entry(
+ __field(void *, lock_addr)
+ __field(unsigned int, flags)
+ ),
+
+ TP_fast_assign(
+ __entry->lock_addr = lock;
+ __entry->flags = flags;
+ ),
+
+ TP_printk("%p (flags=%s)", __entry->lock_addr,
+ __print_flags(__entry->flags, "|",
+ { LCB_F_SPIN, "SPIN" },
+ { LCB_F_READ, "READ" },
+ { LCB_F_WRITE, "WRITE" },
+ { LCB_F_RT, "RT" },
+ { LCB_F_PERCPU, "PERCPU" }
+ ))
+);
+
+TRACE_EVENT(contention_end,
+
+ TP_PROTO(void *lock, int ret),
+
+ TP_ARGS(lock, ret),
+
+ TP_STRUCT__entry(
+ __field(void *, lock_addr)
+ __field(int, ret)
+ ),
+
+ TP_fast_assign(
+ __entry->lock_addr = lock;
+ __entry->ret = ret;
+ ),
+
+ TP_printk("%p (ret=%d)", __entry->lock_addr, __entry->ret)
+);
#endif /* _TRACE_LOCK_H */
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 50036c10b518..08f8fb6a2d1e 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -60,7 +60,6 @@
#include "lockdep_internals.h"
-#define CREATE_TRACE_POINTS
#include <trace/events/lock.h>
#ifdef CONFIG_PROVE_LOCKING
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 5e3585950ec8..ee2fd7614a93 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -30,6 +30,9 @@
#include <linux/debug_locks.h>
#include <linux/osq_lock.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/lock.h>
+
#ifndef CONFIG_PREEMPT_RT
#include "mutex.h"
--
2.35.1.894.gb6a874cedc-goog
