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authorNeilBrown <neilb@suse.com>2016-11-14 16:30:21 +1100
committerShaohua Li <shli@fb.com>2016-11-18 09:34:45 -0800
commit581dbd94da80c845b28666716e30c22c0834756a (patch)
tree2659c3a8eaa694c1eeaead8ce266aae51c0672f6 /drivers/md/bitmap.c
parent109e37653033a5fcd3bf8cab0ed6a7ff433f758a (diff)
downloadlinux-581dbd94da80c845b28666716e30c22c0834756a.tar.bz2
md/bitmap: add blktrace event for writes to the bitmap
We trace wheneven bitmap_unplug() finds that it needs to write to the bitmap, or when bitmap_daemon_work() find there is work to do. This makes it easier to correlate bitmap updates with data writes. Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/bitmap.c')
-rw-r--r--drivers/md/bitmap.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index 1a7f402b79ba..cf77cbf9ed22 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -27,6 +27,7 @@
#include <linux/mount.h>
#include <linux/buffer_head.h>
#include <linux/seq_file.h>
+#include <trace/events/block.h>
#include "md.h"
#include "bitmap.h"
@@ -1008,8 +1009,12 @@ void bitmap_unplug(struct bitmap *bitmap)
need_write = test_and_clear_page_attr(bitmap, i,
BITMAP_PAGE_NEEDWRITE);
if (dirty || need_write) {
- if (!writing)
+ if (!writing) {
bitmap_wait_writes(bitmap);
+ if (bitmap->mddev->queue)
+ blk_add_trace_msg(bitmap->mddev->queue,
+ "md bitmap_unplug");
+ }
clear_page_attr(bitmap, i, BITMAP_PAGE_PENDING);
write_page(bitmap, bitmap->storage.filemap[i], 0);
writing = 1;
@@ -1234,6 +1239,10 @@ void bitmap_daemon_work(struct mddev *mddev)
}
bitmap->allclean = 1;
+ if (bitmap->mddev->queue)
+ blk_add_trace_msg(bitmap->mddev->queue,
+ "md bitmap_daemon_work");
+
/* Any file-page which is PENDING now needs to be written.
* So set NEEDWRITE now, then after we make any last-minute changes
* we will write it.