From: Wu Fengguang <fengguang.wu@intel.com>
Date: Wed, 23 Sep 2009 12:33:40 +0000 (+0800)
Subject: writeback: stop background writeback when below background threshold
X-Git-Tag: v2.6.32-rc1~24^2~9
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d3ddec7635b6fb37cb49e3553bdeea59642be653;p=pandora-kernel.git

writeback: stop background writeback when below background threshold

Treat bdi_start_writeback(0) as a special request to do background write,
and stop such work when we are below the background dirty threshold.

Also simplify the (nr_pages <= 0) checks. Since we already pass in
nr_pages=LONG_MAX for WB_SYNC_ALL and background writes, we don't
need to worry about it being decreased to zero.

Reported-by: Richard Kennedy <richard@rsk.demon.co.uk>
CC: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

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