From 581dbd94da80c845b28666716e30c22c0834756a Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 14 Nov 2016 16:30:21 +1100 Subject: [PATCH] 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 Signed-off-by: Shaohua Li --- drivers/md/bitmap.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) 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 #include #include +#include #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. -- 2.20.1