Re: [PATCH 11/18] block: add bdi flag to indicate risk of io queue underrun
From: Peter Zijlstra <hidden>
Date: 2011-09-06 14:23:26
Also in:
linux-fsdevel, lkml
On Sun, 2011-09-04 at 09:53 +0800, Wu Fengguang wrote:
quoted hunk ↗ jump to hunk
+++ linux-next/mm/page-writeback.c 2011-08-31 14:40:58.000000000 +0800@@ -1067,6 +1067,9 @@ static void balance_dirty_pages(struct a nr_dirty, bdi_thresh, bdi_dirty, start_time); + if (unlikely(!dirty_exceeded && bdi_async_underrun(bdi))) + break; + dirty_ratelimit = bdi->dirty_ratelimit; pos_ratio = bdi_position_ratio(bdi, dirty_thresh, background_thresh, nr_dirty,
So dirty_exceeded looks like: 1109 dirty_exceeded = (bdi_dirty > bdi_thresh) || 1110 (nr_dirty > dirty_thresh); Would it make sense to write it as: if (nr_dirty > dirty_thresh || (nr_dirty > freerun && bdi_dirty > bdi_thresh)) dirty_exceeded = 1; So that we don't actually throttle bdi thingies when we're still in the freerun area? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>