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[185.121.47.193]) by smtp.gmail.com with ESMTPSA id q1-20020ac246e1000000b0050e7be886d9sm2592656lfo.56.2024.01.02.10.47.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 02 Jan 2024 10:47:17 -0800 (PST) From: "Uladzislau Rezki (Sony)" To: linux-mm@kvack.org, Andrew Morton Cc: LKML , Baoquan He , Lorenzo Stoakes , Christoph Hellwig , Matthew Wilcox , "Liam R . Howlett" , Dave Chinner , "Paul E . McKenney" , Joel Fernandes , Uladzislau Rezki , Oleksiy Avramchenko Subject: [PATCH v3 11/11] mm: vmalloc: Add a shrinker to drain vmap pools Date: Tue, 2 Jan 2024 19:46:33 +0100 Message-Id: <20240102184633.748113-12-urezki@gmail.com> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240102184633.748113-1-urezki@gmail.com> References: <20240102184633.748113-1-urezki@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Signed-off-by: Uladzislau Rezki (Sony) --- mm/vmalloc.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index ef534c76daef..e30dabf68263 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -4917,8 +4917,37 @@ static void vmap_init_nodes(void) } } =20 +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 =3D 0, i =3D 0; i < nr_vmap_nodes; i++) { + vn =3D &vmap_nodes[i]; + + for (j =3D 0; j < MAX_VA_SIZE_PAGES; j++) + count +=3D 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 =3D 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 =3D true; + + vmap_node_shrinker =3D shrinker_alloc(0, "vmap-node"); + if (!vmap_node_shrinker) { + pr_err("Failed to allocate vmap-node shrinker!\n"); + return; + } + + vmap_node_shrinker->count_objects =3D vmap_node_shrink_count; + vmap_node_shrinker->scan_objects =3D vmap_node_shrink_scan; + shrinker_register(vmap_node_shrinker); } --=20 2.39.2