[PATCH v5 07/16] memcg: enable accounting for mnt_cache entries
From: Vasily Averin <hidden>
Date: 2021-07-19 10:45:16
Also in:
cgroups, linux-fsdevel
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
The kernel allocates ~400 bytes of 'strcut mount' for any new mount. Creating a new mount namespace clones most of the parent mounts, and this can be repeated many times. Additionally, each mount allocates up to PATH_MAX=4096 bytes for mnt->mnt_devname. It makes sense to account for these allocations to restrict the host's memory consumption from inside the memcg-limited container. Signed-off-by: Vasily Averin <redacted> --- fs/namespace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/namespace.c b/fs/namespace.c
index ab4174a..c6a74e5 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c@@ -203,7 +203,8 @@ static struct mount *alloc_vfsmnt(const char *name) goto out_free_cache; if (name) { - mnt->mnt_devname = kstrdup_const(name, GFP_KERNEL); + mnt->mnt_devname = kstrdup_const(name, + GFP_KERNEL_ACCOUNT); if (!mnt->mnt_devname) goto out_free_id; }
@@ -4222,7 +4223,7 @@ void __init mnt_init(void) int err; mnt_cache = kmem_cache_create("mnt_cache", sizeof(struct mount), - 0, SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); + 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL); mount_hashtable = alloc_large_system_hash("Mount-cache", sizeof(struct hlist_head),
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1.8.3.1