From 46fa67175c2ec7a6bba2274f02ea23102d3ba5e6 Mon Sep 17 00:00:00 2001 From: Ridong Chen Date: Wed, 26 Aug 2026 20:44:09 +0800 Subject: [PATCH] mm/vmscan: drop the combined limit gate in __node_reclaim() __node_reclaim() is called from two paths: node_reclaim() and user_proactive_reclaim(). node_reclaim() already bails out early unless node_pagecache_reclaimable() is over pgdat->min_unmapped_pages or the reclaimable slab is over pgdat->min_slab_pages. The identical check inside __node_reclaim() that guards the shrink_node() loop is therefore redundant for this path. user_proactive_reclaim() is proactive reclaim driven by userspace and should not be gated by the per-node min_unmapped_pages / min_slab_pages limits at all [1]. With the gate in place, a proactive request is silently turned into a no-op whenever the node happens to sit below both thresholds. Drop the gate in __node_reclaim() and always run the shrink_node() loop. The node_reclaim() path is unchanged, since its caller has already applied the same test; the proactive path is no longer wrongly gated. Link: https://lore.kernel.org/20260826124409.35569-1-ridong.chen@linux.dev Link: https://sashiko.dev/#/patchset/20260723045718.2052070-1-ridong.chen@linux.dev [1] Fixes: b980077899ea ("mm: introduce per-node proactive reclaim interface") Acked-by: Johannes Weiner Signed-off-by: Ridong Chen Signed-off-by: Andrew Morton Acked-by: Michal Hocko Acked-by: Shakeel Butt Acked-by: Davidlohr Bueso Assisted-by: Claude:claude-opus-4-8 Cc: Axel Rasmussen Cc: Barry Song Cc: David Hildenbrand Cc: Kairui Song Cc: Lorenzo Stoakes Cc: Roman Gushchin Cc: Wei Xu Cc: Yuanchu Xie --- mm/vmscan.c | 13 +++---------- 1 file changed, 3 insertions(+), 10 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index f11491ee9ed5..6dff207ad8c6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -7851,16 +7851,9 @@ static unsigned long __node_reclaim(struct pglist_data *pgdat, noreclaim_flag = memalloc_noreclaim_save(); set_task_reclaim_state(p, &sc->reclaim_state); - if (node_pagecache_reclaimable(pgdat) > pgdat->min_unmapped_pages || - node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B) > pgdat->min_slab_pages) { - /* - * Free memory by calling shrink node with increasing - * priorities until we have enough memory freed. - */ - do { - shrink_node(pgdat, sc); - } while (sc->nr_reclaimed < nr_pages && --sc->priority >= 0); - } + do { + shrink_node(pgdat, sc); + } while (sc->nr_reclaimed < nr_pages && --sc->priority >= 0); set_task_reclaim_state(p, NULL); memalloc_noreclaim_restore(noreclaim_flag);