From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vasily Averin Subject: [PATCH v4 09/16] memcg: enable accounting for mnt_cache entries Date: Wed, 28 Apr 2021 09:53:06 +0300 Message-ID: <11cfc0f7-f79b-6bc5-dd75-ce7e5c56df35@virtuozzo.com> References: <8664122a-99d3-7199-869a-781b21b7e712@virtuozzo.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=virtuozzo.com; s=relay; h=Content-Type:MIME-Version:Date:Message-ID:Subject :From; bh=afhYD1X2+3SAdjfj4AmF+/Ff2fiTPNdUADuOJ81ts1A=; b=gsxDTXzzgbBEzVpL+QP 6JytlJ0SRi9f+pljTBz2z4B8VMvDkvi83yakaHmlbsRNTl36izCeHOYfvvCW8gBDMa4qV/JoxLOLz KRzfMuu2iblkVr2VrWQvY4dMcaOmXrzjGCbqQ2E5R3JzAw+URaG9lNBQoPDUGapKDx2PVIEOjvs= In-Reply-To: <8664122a-99d3-7199-869a-781b21b7e712-5HdwGun5lf+gSpxsJD1C4w@public.gmane.org> Content-Language: en-US List-ID: Content-Type: text/plain; charset="us-ascii" To: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Michal Hocko , Shakeel Butt , Johannes Weiner , Vladimir Davydov Cc: Roman Gushchin , Alexander Viro , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 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 --- fs/namespace.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/namespace.c b/fs/namespace.c index 5ecfa349..fc1b50d 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; } @@ -4213,7 +4214,7 @@ 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), -- 1.8.3.1