The patch titled
Subject: mm: memory_hotplug: drop memoryless node from fallback lists
has been added to the -mm mm-unstable branch. Its filename is
mm-memory_hotplug-drop-memoryless-node-from-fallback-lists.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-memory_hotplug-drop-memoryless-node-from-fallback-lists.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: memory_hotplug: drop memoryless node from fallback lists
Date: Thu, 19 Oct 2023 18:43:55 +0800
In offline_pages(), if a node becomes memoryless, we will clear its
N_MEMORY state by calling node_states_clear_node(). But we do this after
rebuilding the zonelists by calling build_all_zonelists(), which will
cause this memoryless node to still be in the fallback list of other
nodes. This will incur some runtime overhead.
To drop memoryless node from fallback lists in this case, just call
node_states_clear_node() before calling build_all_zonelists().
Link: https://lkml.kernel.org/r/9f1dbe7ee1301c7163b2770e32954ff5e3ecf2c4.1697711415.git.zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Cc: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Cc: "Huang, Ying" <ying.huang@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory_hotplug.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/mm/memory_hotplug.c~mm-memory_hotplug-drop-memoryless-node-from-fallback-lists
+++ a/mm/memory_hotplug.c
@@ -2012,12 +2012,16 @@ int __ref offline_pages(unsigned long st
/* reinitialise watermarks and update pcp limits */
init_per_zone_wmark_min();
+ /*
+ * Make sure to mark the node as memory-less before rebuilding the zone
+ * list. Otherwise this node would still appear in the fallback lists.
+ */
+ node_states_clear_node(node, &arg);
if (!populated_zone(zone)) {
zone_pcp_reset(zone);
build_all_zonelists(NULL);
}
- node_states_clear_node(node, &arg);
if (arg.status_change_nid >= 0) {
kcompactd_stop(node);
kswapd_stop(node);
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-page_alloc-skip-memoryless-nodes-entirely.patch
mm-memory_hotplug-drop-memoryless-node-from-fallback-lists.patch
