+ vmalloc-use-for_each_vmap_node-in-purge-vmap-area.patch added to mm-new branch

+ vmalloc-use-for_each_vmap_node-in-purge-vmap-area.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: vmalloc: use for_each_vmap_node() in purge-vmap-area
has been added to the -mm mm-new branch.  Its filename is
     vmalloc-use-for_each_vmap_node-in-purge-vmap-area.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/vmalloc-use-for_each_vmap_node-in-purge-vmap-area.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Subject: vmalloc: use for_each_vmap_node() in purge-vmap-area
Date: Tue, 8 Apr 2025 17:15:49 +0200

Update a __purge_vmap_area_lazy() to use introduced helper.  This is last
place in vmalloc code.  Also this patch introduces an extra function which
is node_to_id() that converts a vmap_node pointer to an index in array.

__purge_vmap_area_lazy() requires that extra function.

Link: https://lkml.kernel.org/r/20250408151549.77937-3-urezki@gmail.com
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Christop Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmalloc.c |   19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

--- a/mm/vmalloc.c~vmalloc-use-for_each_vmap_node-in-purge-vmap-area
+++ a/mm/vmalloc.c
@@ -923,6 +923,19 @@ id_to_node(unsigned int id)
 	return &vmap_nodes[id % nr_vmap_nodes];
 }
 
+static inline unsigned int
+node_to_id(struct vmap_node *node)
+{
+	/* Pointer arithmetic. */
+	unsigned int id = node - vmap_nodes;
+
+	if (likely(id < nr_vmap_nodes))
+		return id;
+
+	WARN_ONCE(1, "An address 0x%p is out-of-bounds.\n", node);
+	return 0;
+}
+
 /*
  * We use the value 0 to represent "no node", that is why
  * an encoded value will be the node-id incremented by 1.
@@ -2259,9 +2272,7 @@ static bool __purge_vmap_area_lazy(unsig
 	 */
 	purge_nodes = CPU_MASK_NONE;
 
-	for (i = 0; i < nr_vmap_nodes; i++) {
-		vn = &vmap_nodes[i];
-
+	for_each_vmap_node(vn) {
 		INIT_LIST_HEAD(&vn->purge_list);
 		vn->skip_populate = full_pool_decay;
 		decay_va_pool_node(vn, full_pool_decay);
@@ -2280,7 +2291,7 @@ static bool __purge_vmap_area_lazy(unsig
 		end = max(end, list_last_entry(&vn->purge_list,
 			struct vmap_area, list)->va_end);
 
-		cpumask_set_cpu(i, &purge_nodes);
+		cpumask_set_cpu(node_to_id(vn), &purge_nodes);
 	}
 
 	nr_purge_nodes = cpumask_weight(&purge_nodes);
_

Patches currently in -mm which might be from urezki@gmail.com are

vmalloc-add-for_each_vmap_node-helper.patch
vmalloc-switch-to-for_each_vmap_node-helper.patch
vmalloc-use-for_each_vmap_node-in-purge-vmap-area.patch