bdi: use deferable timer for sync_supers task
sync_supers task currently wakes up periodically for superblock
writeback. This hurts power on battery driven devices. This patch
turns this housekeeping timer into a deferable timer so that it
does not fire when system is really idle.
CRs-Fixed: 353700
Change-Id: Idc7953b5d0580546808bc5832291ca570837ee7f
Signed-off-by: Yong Wang <yong.y.wang@intel.com>
Signed-off-by: Xia Wu <xia.wu@intel.com>
Signed-off-by: Krishna Vanka <kvanka@codeaurora.org>
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index dd8e2aa..fc15fb1 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -253,7 +253,9 @@
sync_supers_tsk = kthread_run(bdi_sync_supers, NULL, "sync_supers");
BUG_ON(IS_ERR(sync_supers_tsk));
- setup_timer(&sync_supers_timer, sync_supers_timer_fn, 0);
+ init_timer_deferrable(&sync_supers_timer);
+ sync_supers_timer.function = sync_supers_timer_fn;
+ sync_supers_timer.data = 0;
bdi_arm_supers_timer();
err = bdi_init(&default_backing_dev_info);