From patchwork Mon Jul 26 19:00:48 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vasily Averin X-Patchwork-Id: 12400621 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE5AEC432BE for ; Mon, 26 Jul 2021 19:00:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 950AE60C41 for ; Mon, 26 Jul 2021 19:00:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233011AbhGZSUZ (ORCPT ); Mon, 26 Jul 2021 14:20:25 -0400 Received: from relay.sw.ru ([185.231.240.75]:55224 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232923AbhGZSUV (ORCPT ); Mon, 26 Jul 2021 14:20:21 -0400 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=bgm9OS9KolAL5uXELhf+0mY9tqnepOoZ0HrSZvp8ULM=; b=fJg7jHp0nLOCKiZRvSW shjBPrvwZFDautLw7asTY58rHCktPPFXvYpeUmXDGP4Llrjo6vcM76twwpiQCwRt4LzY/MYnhlRTp IfRU9n/mBlGXktU/RJIw05ivHFKfA+terzsuXL2OkgTq2FebvFmw+g3OU0PHQOXFWgFdo1gcbrU=; Received: from [10.93.0.56] by relay.sw.ru with esmtp (Exim 4.94.2) (envelope-from ) id 1m85qL-005JUI-1U; Mon, 26 Jul 2021 22:00:49 +0300 From: Vasily Averin Subject: [PATCH v6 07/16] memcg: enable accounting for mnt_cache entries To: Andrew Morton Cc: cgroups@vger.kernel.org, Michal Hocko , Shakeel Butt , Johannes Weiner , Vladimir Davydov , Roman Gushchin , Alexander Viro , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org References: <9bf9d9bd-03b1-2adb-17b4-5d59a86a9394@virtuozzo.com> Message-ID: <8d06c97c-451f-474b-026f-b898e2566daf@virtuozzo.com> Date: Mon, 26 Jul 2021 22:00:48 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.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 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),