writeback: move over_bground_thresh() to mm/page-writeback.c
and rename it to wb_over_bg_thresh(). The function is closely tied to
the dirty throttling mechanism implemented in page-writeback.c. This
relocation will allow future updates necessary for cgroup writeback
support.
While at it, add function comment.
This is pure reorganization and doesn't introduce any behavioral
changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Greg Thelen <gthelen@google.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 51c8a5b..da35587 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1071,22 +1071,6 @@
return nr_pages - work.nr_pages;
}
-static bool over_bground_thresh(struct bdi_writeback *wb)
-{
- unsigned long background_thresh, dirty_thresh;
-
- global_dirty_limits(&background_thresh, &dirty_thresh);
-
- if (global_page_state(NR_FILE_DIRTY) +
- global_page_state(NR_UNSTABLE_NFS) > background_thresh)
- return true;
-
- if (wb_stat(wb, WB_RECLAIMABLE) > wb_calc_thresh(wb, background_thresh))
- return true;
-
- return false;
-}
-
/*
* Explicit flushing or periodic writeback of "old" data.
*
@@ -1136,7 +1120,7 @@
* For background writeout, stop when we are below the
* background dirty threshold
*/
- if (work->for_background && !over_bground_thresh(wb))
+ if (work->for_background && !wb_over_bg_thresh(wb))
break;
/*
@@ -1227,7 +1211,7 @@
static long wb_check_background_flush(struct bdi_writeback *wb)
{
- if (over_bground_thresh(wb)) {
+ if (wb_over_bg_thresh(wb)) {
struct wb_writeback_work work = {
.nr_pages = LONG_MAX,