[PATCH 0/2] improve per-node allocation and reclaim visibility
From: JP Kobryn
Date: Wed Feb 11 2026 - 23:52:03 EST
We sometimes find ourselves in situations where reclaim kicks in, yet there
is free memory available on the system. One possible explanation is that a
NUMA node under pressure has triggered the reclaim. This NUMA imbalance
scenario could be made easier to diagnose if we had better visibility.
This series aims to provide that visibility by accounting for the cause and
effect of the imbalance. First, the addition of new node stats allows for
tracking of allocations done on a per-policy basis. If a node is under
pressure, these stats can help reveal the cause of how it got there.
Second, the stats associated with reclaim are changed from vm_event_item to
node_stat_item. Having the pgsteal and pgscan counters tracked on a
per-node basis reveals the effect of any pressure, and allows us to quickly
narrow down the affected node(s).
JP Kobryn (2):
mm/mempolicy: track page allocations per mempolicy
mm: move pgscan and pgsteal to node stats
drivers/virtio/virtio_balloon.c | 8 ++++----
include/linux/mmzone.h | 21 +++++++++++++++++++
include/linux/vm_event_item.h | 12 -----------
mm/memcontrol.c | 36 ++++++++++++++++++---------------
mm/mempolicy.c | 30 +++++++++++++++++++++++++--
mm/vmscan.c | 32 +++++++++++------------------
mm/vmstat.c | 33 +++++++++++++++++++-----------
7 files changed, 106 insertions(+), 66 deletions(-)
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2.47.3