writeback: stabilize bdi->dirty_ratelimit

[deliverable/linux.git] / include / linux / backing-dev.h

diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index dff0ff78e8780ce40b1787e449656215916e530f..c3b92010d894aa1a7ec061a32817ff256c9873f5 100644 (file)
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -83,8 +83,11 @@ struct backing_dev_info {
        /*
         * The base dirty throttle rate, re-calculated on every 200ms.
         * All the bdi tasks' dirty rate will be curbed under it.
+        * @dirty_ratelimit tracks the estimated @balanced_dirty_ratelimit
+        * in small steps and is much more smooth/stable than the latter.
         */
        unsigned long dirty_ratelimit;
+       unsigned long balanced_dirty_ratelimit;
 
        struct prop_local_percpu completions;
        int dirty_exceeded;