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... ------------------------------------------------- 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"); } -- 2.25.1