Commit f09b00d3 authored by Jens Axboe's avatar Jens Axboe
Browse files

writeback: add some debug inode list counters to bdi stats 



Add some debug entries to be able to inspect the internal state of
the writeback details.

Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent d0bceac7

mm/backing-dev.c

+34 −4
Original line number Diff line number Diff line
@@ -52,9 +52,29 @@ static void bdi_debug_init(void) 
static int bdi_debug_stats_show(struct seq_file *m, void *v)

{

	struct backing_dev_info *bdi = m->private;

	struct bdi_writeback *wb;

	unsigned long background_thresh;

	unsigned long dirty_thresh;

	unsigned long bdi_thresh;

	unsigned long nr_dirty, nr_io, nr_more_io, nr_wb;

	struct inode *inode;



	/*

	 * inode lock is enough here, the bdi->wb_list is protected by

	 * RCU on the reader side

	 */

	nr_wb = nr_dirty = nr_io = nr_more_io = 0;

	spin_lock(&inode_lock);

	list_for_each_entry(wb, &bdi->wb_list, list) {

		nr_wb++;

		list_for_each_entry(inode, &wb->b_dirty, i_list)

			nr_dirty++;

		list_for_each_entry(inode, &wb->b_io, i_list)

			nr_io++;

		list_for_each_entry(inode, &wb->b_more_io, i_list)

			nr_more_io++;

	}

	spin_unlock(&inode_lock);



	get_dirty_limits(&background_thresh, &dirty_thresh, &bdi_thresh, bdi);
@@ -64,12 +84,22 @@ static int bdi_debug_stats_show(struct seq_file *m, void *v) 
		   "BdiReclaimable:   %8lu kB\n"

		   "BdiDirtyThresh:   %8lu kB\n"

		   "DirtyThresh:      %8lu kB\n"

		   "BackgroundThresh: %8lu kB\n",

		   "BackgroundThresh: %8lu kB\n"

		   "WriteBack threads:%8lu\n"

		   "b_dirty:          %8lu\n"

		   "b_io:             %8lu\n"

		   "b_more_io:        %8lu\n"

		   "bdi_list:         %8u\n"

		   "state:            %8lx\n"

		   "wb_mask:          %8lx\n"

		   "wb_list:          %8u\n"

		   "wb_cnt:           %8u\n",

		   (unsigned long) K(bdi_stat(bdi, BDI_WRITEBACK)),

		   (unsigned long) K(bdi_stat(bdi, BDI_RECLAIMABLE)),

		   K(bdi_thresh),

		   K(dirty_thresh),

		   K(background_thresh));

		   K(bdi_thresh), K(dirty_thresh),

		   K(background_thresh), nr_wb, nr_dirty, nr_io, nr_more_io,

		   !list_empty(&bdi->bdi_list), bdi->state, bdi->wb_mask,

		   !list_empty(&bdi->wb_list), bdi->wb_cnt);

#undef K



	return 0;