The patch titled
Subject: mm: vmalloc: add a shrinker to drain vmap pools
has been added to the -mm mm-unstable branch. Its filename is
mm-vmalloc-add-a-shrinker-to-drain-vmap-pools.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmalloc-add-a-shrinker-to-drain-vmap-pools.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: "Uladzislau Rezki (Sony)" <urezki@xxxxxxxxx>
Subject: mm: vmalloc: add a shrinker to drain vmap pools
Date: Tue, 2 Jan 2024 19:46:33 +0100
The added shrinker is used to return back current cached VAs into a global
vmap space, when a system enters into a low memory mode.
Link: https://lkml.kernel.org/r/20240102184633.748113-12-urezki@xxxxxxxxx
Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
Cc: Kazuhito Hagio <k-hagio-ab@xxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Dave Chinner <david@xxxxxxxxxxxxx>
Cc: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
Cc: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Oleksiy Avramchenko <oleksiy.avramchenko@xxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/vmalloc.c | 39 +++++++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
--- a/mm/vmalloc.c~mm-vmalloc-add-a-shrinker-to-drain-vmap-pools
+++ a/mm/vmalloc.c
@@ -4917,8 +4917,37 @@ static void vmap_init_nodes(void)
}
}
+static unsigned long
+vmap_node_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
+{
+ unsigned long count;
+ struct vmap_node *vn;
+ int i, j;
+
+ for (count = 0, i = 0; i < nr_vmap_nodes; i++) {
+ vn = &vmap_nodes[i];
+
+ for (j = 0; j < MAX_VA_SIZE_PAGES; j++)
+ count += READ_ONCE(vn->pool[j].len);
+ }
+
+ return count ? count : SHRINK_EMPTY;
+}
+
+static unsigned long
+vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
+{
+ int i;
+
+ for (i = 0; i < nr_vmap_nodes; i++)
+ decay_va_pool_node(&vmap_nodes[i], true);
+
+ return SHRINK_STOP;
+}
+
void __init vmalloc_init(void)
{
+ struct shrinker *vmap_node_shrinker;
struct vmap_area *va;
struct vmap_node *vn;
struct vm_struct *tmp;
@@ -4966,4 +4995,14 @@ void __init vmalloc_init(void)
*/
vmap_init_free_space();
vmap_initialized = true;
+
+ vmap_node_shrinker = shrinker_alloc(0, "vmap-node");
+ if (!vmap_node_shrinker) {
+ pr_err("Failed to allocate vmap-node shrinker!\n");
+ return;
+ }
+
+ vmap_node_shrinker->count_objects = vmap_node_shrink_count;
+ vmap_node_shrinker->scan_objects = vmap_node_shrink_scan;
+ shrinker_register(vmap_node_shrinker);
}
_
Patches currently in -mm which might be from urezki@xxxxxxxxx are
mm-vmalloc-add-va_alloc-helper.patch
mm-vmalloc-rename-adjust_va_to_fit_type-function.patch
mm-vmalloc-move-vmap_init_free_space-down-in-vmallocc.patch
mm-vmalloc-remove-global-vmap_area_root-rb-tree.patch
mm-vmalloc-remove-global-purge_vmap_area_root-rb-tree.patch
mm-vmalloc-offload-free_vmap_area_lock-lock.patch
mm-vmalloc-support-multiple-nodes-in-vread_iter.patch
mm-vmalloc-support-multiple-nodes-in-vmallocinfo.patch
mm-vmalloc-set-nr_nodes-based-on-cpus-in-a-system.patch
mm-vmalloc-add-a-shrinker-to-drain-vmap-pools.patch
