xen: avoid allocation causing potential swap activity on the resume path
commitb3831cb55d383e8eb55d3b56c715fb48459b87c9
authorIan Campbell <ian.campbell@citrix.com>
Tue, 25 May 2010 09:45:35 +0000 (25 10:45 +0100)
committerIan Campbell <ian.campbell@citrix.com>
Thu, 3 Jun 2010 08:34:45 +0000 (3 09:34 +0100)
treef0f7f26534bca491dc9570f2243df817e982feb4
parentcd52e17ea8278f8449b6174a8e5ed439a2e44ffb
xen: avoid allocation causing potential swap activity on the resume path

Since the device we are resuming could be the device containing the
swap device we should ensure that the allocation cannot cause
IO.

On resume, this path is triggered when the running system tries to
continue using its devices.  If it cannot then the resume will fail;
to try to avoid this we let it dip into the emergency pools.

The majority of these changes were made when linux-2.6.18-xen.hg
changeset e8b49cfbdac0 was ported upstream in
a144ff09bc52ef3f3684ed23eadc9c7c0e57b3aa but somehow this hunk was
dropped.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Stable Kernel <stable@kernel.org> # .32.x
drivers/xen/xenbus/xenbus_xs.c