block: add block_{touch|dirty}_buffer tracepoint
The former is triggered from touch_buffer() and the latter
mark_buffer_dirty().
This is part of tracepoint additions to improve visiblity into
dirtying / writeback operations for io tracer and userland.
v2: Transformed writeback_dirty_buffer to block_dirty_buffer and made
it share TP definition with block_touch_buffer.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/fs/buffer.c b/fs/buffer.c
index a8c2dfb..87ff335 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -41,6 +41,7 @@
#include <linux/bitops.h>
#include <linux/mpage.h>
#include <linux/bit_spinlock.h>
+#include <trace/events/block.h>
static int fsync_buffers_list(spinlock_t *lock, struct list_head *list);
@@ -55,6 +56,7 @@
inline void touch_buffer(struct buffer_head *bh)
{
+ trace_block_touch_buffer(bh);
mark_page_accessed(bh->b_page);
}
EXPORT_SYMBOL(touch_buffer);
@@ -1119,6 +1121,8 @@
{
WARN_ON_ONCE(!buffer_uptodate(bh));
+ trace_block_dirty_buffer(bh);
+
/*
* Very *carefully* optimize the it-is-already-dirty case.
*