On Fri, Jan 28, 2011 at 12:26:08PM +0900, KAMEZAWA Hiroyuki wrote:

From: KAMEZAWA Hiroyuki <redacted>

When THP is used, Hugepage size charge can happen. It's not handled
correctly in mem_cgroup_do_charge(). For example, THP can fallback
to small page allocation when HUGEPAGE allocation seems difficult
or busy, but memory cgroup doesn't understand it and continue to
try HUGEPAGE charging. And the worst thing is memory cgroup
believes 'memory reclaim succeeded' if limit - usage > PAGE_SIZE.

By this, khugepaged etc...can goes into inifinite reclaim loop
if tasks in memcg are busy.

After this patch 
 - Hugepage allocation will fail if 1st trial of page reclaim fails.

Changelog:
 - make changes small. removed renaming codes.

Signed-off-by: KAMEZAWA Hiroyuki <redacted>
---
 mm/memcontrol.c |   28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

Was there something wrong with my oneline fix?

Really, there is no way to make this a beautiful fix.  The way this
function is split up makes no sense, and the constant addition of more
and more flags just to correctly communicate with _one callsite_
should be an obvious hint.

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