memory-hotplug: auto offline page_cgroup when onlining memory block failed

memory-hotplug: auto offline page_cgroup when onlining memory block failed

When a memory block is onlined, we will try allocate memory on that node
to store page_cgroup.  If onlining the memory block failed, we don't
offline the page cgroup, and we have no chance to offline this page cgroup
unless the memory block is onlined successfully again.  It will cause that
we can't hot-remove the memory device on that node, because some memory is
used to store page cgroup.  If onlining the memory block is failed, there
is no need to stort page cgroup for this memory.  So auto offline
page_cgroup when onlining memory block failed.

Signed-off-by: Wen Congyang <[email protected]>
Cc: David Rientjes <[email protected]>
Cc: Jiang Liu <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Christoph Lameter <[email protected]>
Cc: Minchan Kim <[email protected]>
Acked-by: KOSAKI Motohiro <[email protected]>
Cc: Yasuaki Ishimatsu <[email protected]>
Cc: Dave Hansen <[email protected]>
Cc: Mel Gorman <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>