From: "Uladzislau Rezki (Sony)" urezki@gmail.com
mainline inclusion from mainline-v6.9-rc1 commit 7679ba6b36dbb300b757b672d6a32a606499e14b category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I9CHG1 CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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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@gmail.com Signed-off-by: Uladzislau Rezki (Sony) urezki@gmail.com Cc: Kazuhito Hagio k-hagio-ab@nec.com Cc: Baoquan He bhe@redhat.com Cc: Christoph Hellwig hch@lst.de Cc: Dave Chinner david@fromorbit.com Cc: Joel Fernandes (Google) joel@joelfernandes.org Cc: Liam R. Howlett Liam.Howlett@oracle.com Cc: Lorenzo Stoakes lstoakes@gmail.com Cc: Matthew Wilcox (Oracle) willy@infradead.org Cc: Oleksiy Avramchenko oleksiy.avramchenko@sony.com Cc: Paul E. McKenney paulmck@kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org (cherry picked from commit 7679ba6b36dbb300b757b672d6a32a606499e14b) Signed-off-by: Kefeng Wang wangkefeng.wang@huawei.com
[Since the struct shrinker was not introduced in OLK6.6, the vmalloc lock contention series of patches conflict. Fix this problem by introducing a struct shrinker.]
Conflicts: mm/vmalloc.c
Signed-off-by: ZhangPeng zhangpeng362@huawei.com --- mm/vmalloc.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+)
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 0bbd5eff03f4..a1b67d5b9a5b 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5195,6 +5195,39 @@ 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; +} + +static struct shrinker vmap_node_shrinker = { + .count_objects = vmap_node_shrink_count, + .scan_objects = vmap_node_shrink_scan, +}; + void __init vmalloc_init(void) { struct vmap_area *va; @@ -5244,4 +5277,7 @@ void __init vmalloc_init(void) */ vmap_init_free_space(); vmap_initialized = true; + + if (register_shrinker(&vmap_node_shrinker, "vmap-node")) + pr_err("Failed to allocate vmap-node shrinker!\n"); }