From: Mel Gorman <mel@csn.ul.ie>
Date: Tue, 26 Oct 2010 21:21:41 +0000 (-0700)
Subject: writeback: account for time spent congestion_waited
X-Git-Tag: v2.6.37-rc1~105^2~141
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=52bb9198668968506f9d12bf35d7f5d3f094921e;p=pandora-kernel.git

writeback: account for time spent congestion_waited

There is strong evidence to indicate a lot of time is being spent in
congestion_wait(), some of it unnecessarily.  This patch adds a tracepoint
for congestion_wait to record when congestion_wait() was called, how long
the timeout was for and how long it actually slept.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Reviewed-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

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