The patch titled
mm/memory_hotplug.c: fix building of node hotplug zonelist
has been added to the -mm tree. Its filename is
mm-memory_hotplugc-fix-building-of-node-hotplug-zonelist.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find
out what to do about this
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: mm/memory_hotplug.c: fix building of node hotplug zonelist
From: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
During memory hotplug we refresh zonelists when we online a page in a new
zone. It means that the node's zonelist is not initialized until pages
are onlined. So for example, "nid" passed by MEM_GOING_ONLINE notifier
will point to NODE_DATA(nid) which has no zone fallback list. Moreover,
if we hot-add cpu-only nodes, alloc_pages() will do no fallback.
This patch makes a zonelist when a new pgdata is available.
Note: in production, at fujitsu, memory should be onlined before cpu
and our server didn't have any memory-less nodes and had no problems.
But recent changes in MEM_GOING_ONLINE+page_cgroup
will access not initialized zonelist of node.
Anyway, there are memory-less node and we need some care.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Dave Hansen <dave@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 6 ++++++
1 file changed, 6 insertions(+)
diff -puN mm/memory_hotplug.c~mm-memory_hotplugc-fix-building-of-node-hotplug-zonelist mm/memory_hotplug.c
--- a/mm/memory_hotplug.c~mm-memory_hotplugc-fix-building-of-node-hotplug-zonelist
+++ a/mm/memory_hotplug.c
@@ -494,6 +494,12 @@ static pg_data_t __ref *hotadd_new_pgdat
/* init node's zones as empty zones, we don't have any present pages.*/
free_area_init_node(nid, zones_size, start_pfn, zholes_size);
+ /*
+ * The node we allocated has no zone fallback lists. For avoiding
+ * to access not-initialized zonelist, build here.
+ */
+ build_all_zonelists(NULL);
+
return pgdat;
}
_
Patches currently in -mm which might be from kamezawa.hiroyu@xxxxxxxxxxxxxx are
vmscanmemcg-memcg-aware-swap-token.patch
vmscanmemcg-memcg-aware-swap-token-fix.patch
vmscan-implement-swap-token-trace.patch
vmscan-implement-swap-token-priority-aging.patch
memcg-add-documentation-for-the-memorynumastat-api.patch
memcg-add-documentation-for-the-memorynumastat-api-fix.patch
mm-increase-reclaim_distance-to-30.patch
mm-fix-wrong-kunmap_atomic-pointer.patch
mm-memory_hotplugc-fix-building-of-node-hotplug-zonelist.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
