Re: [PATCH] writeback: Fix performance regression in wb_over_bg_thresh()

[Tejun Heo]

On Thu, Mar 10, 2016 at 01:12:39AM -0500, Howard Cochran wrote:
> Commit 947e9762a8dd ("writeback: update wb_over_bg_thresh() to use
> wb_domain aware operations") unintentionally changed this function's
> meaning from "are there more dirty pages than the background writeback
> threshold" to "are there more dirty pages than the writeback threshold".
> The background writeback threshold is typically half of the writeback
> threshold, so this had the effect of raising the number of dirty pages
> required to cause a writeback worker to perform background writeout.
...
> Fixes: 947e9762a8dd ("writeback: update wb_over_bg_thresh() to use
>                      wb_domain aware operations")
> Signed-off-by: Howard Cochran <hcochran@xxxxxxxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Jens Axboe <axboe@xxxxxxxxx>

Acked-by: Tejun Heo <tj@xxxxxxxxxx>

Thanks!

-- 
tejun