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mm-vmscan-drop-the-combined-limit-gate-in-__node_reclaim.patch removed from -mm tree

merged mm-stable Andrew Morton 1 participant 1 message Oct 7

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The quilt patch titled
Subject: mm/vmscan: drop the combined limit gate in __node_reclaim()
has been removed from the -mm tree. Its filename was
mm-vmscan-drop-the-combined-limit-gate-in-__node_reclaim.patch

This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Ridong Chen <[email protected]>
Subject: mm/vmscan: drop the combined limit gate in __node_reclaim()
Date: Wed, 26 Aug 2026 20:44:09 +0800

__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.

Fixes b980077899ea ("mm: introduce per-node proactive reclaim interface")
Assisted-by Claude:claude-opus-4-8
Cc Axel Rasmussen <[email protected]>
Cc Barry Song <[email protected]>
Cc David Hildenbrand <[email protected]>
Cc Kairui Song <[email protected]>
Cc Lorenzo Stoakes <[email protected]>
Cc Roman Gushchin <[email protected]>
Cc Wei Xu <[email protected]>
Cc Yuanchu Xie <[email protected]>

---

 mm/vmscan.c |   13 +++----------
 1 file changed, 3 insertions(+), 10 deletions(-)
mm/vmscan.c renamed from mm/vmscan.c~mm-vmscan-drop-the-combined-limit-gate-in-__node_reclaim +3 -10
@@ -7851,16 +7851,9 @@ static unsigned long __node_reclaim(stru
 	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);

_

Patches currently in -mm which might be from [email protected] are

mm-page_counter-avoid-integer-overflow-in-effective_protection.patch mm-mglru-fix-ineffective-memory-protection-for-non-kswapd-reclaim.patch mm-vmscan-put-rotation-missed-folios-at-the-lru-tail.patch