From mboxrd@z Thu Jan 1 00:00:00 1970 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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 EBA9FC31E5B for ; Wed, 19 Jun 2019 17:16:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CA1C220657 for ; Wed, 19 Jun 2019 17:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730039AbfFSRQl (ORCPT ); Wed, 19 Jun 2019 13:16:41 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53976 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726251AbfFSRQl (ORCPT ); Wed, 19 Jun 2019 13:16:41 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 52BE4821C3; Wed, 19 Jun 2019 17:16:35 +0000 (UTC) Received: from llong.com (dhcp-17-85.bos.redhat.com [10.18.17.85]) by smtp.corp.redhat.com (Postfix) with ESMTP id 15C105D71B; Wed, 19 Jun 2019 17:16:29 +0000 (UTC) From: Waiman Long To: Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Michal Hocko , Roman Gushchin , Johannes Weiner , Shakeel Butt , Vladimir Davydov , Waiman Long Subject: [PATCH v2] mm, memcg: Add a memcg_slabinfo debugfs file Date: Wed, 19 Jun 2019 13:16:21 -0400 Message-Id: <20190619171621.26209-1-longman@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.28]); Wed, 19 Jun 2019 17:16:40 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There are concerns about memory leaks from extensive use of memory cgroups as each memory cgroup creates its own set of kmem caches. There is a possiblity that the memcg kmem caches may remain even after the memory cgroups have been offlined. Therefore, it will be useful to show the status of each of memcg kmem caches. This patch introduces a new /memcg_slabinfo file which is somewhat similar to /proc/slabinfo in format, but lists only information about kmem caches that have child memcg kmem caches. Information available in /proc/slabinfo are not repeated in memcg_slabinfo. A portion of a sample output of the file was: # rpc_inode_cache root 13 51 1 1 rpc_inode_cache 48 0 0 0 0 fat_inode_cache root 1 45 1 1 fat_inode_cache 41 2 45 1 1 xfs_inode root 770 816 24 24 xfs_inode 92 22 34 1 1 xfs_inode 88:dead 1 34 1 1 xfs_inode 89:dead 23 34 1 1 xfs_inode 85 4 34 1 1 xfs_inode 84 9 34 1 1 The css id of the memcg is also listed. If a memcg is not online, the tag ":dead" will be attached as shown above. Suggested-by: Shakeel Butt Signed-off-by: Waiman Long --- mm/slab_common.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/mm/slab_common.c b/mm/slab_common.c index 58251ba63e4a..2bca1558a722 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -1498,6 +1499,62 @@ static int __init slab_proc_init(void) return 0; } module_init(slab_proc_init); + +#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_MEMCG_KMEM) +/* + * Display information about kmem caches that have child memcg caches. + */ +static int memcg_slabinfo_show(struct seq_file *m, void *unused) +{ + struct kmem_cache *s, *c; + struct slabinfo sinfo; + + mutex_lock(&slab_mutex); + seq_puts(m, "# "); + seq_puts(m, " \n"); + list_for_each_entry(s, &slab_root_caches, root_caches_node) { + /* + * Skip kmem caches that don't have any memcg children. + */ + if (list_empty(&s->memcg_params.children)) + continue; + + memset(&sinfo, 0, sizeof(sinfo)); + get_slabinfo(s, &sinfo); + seq_printf(m, "%-17s root %6lu %6lu %6lu %6lu\n", + cache_name(s), sinfo.active_objs, sinfo.num_objs, + sinfo.active_slabs, sinfo.num_slabs); + + for_each_memcg_cache(c, s) { + struct cgroup_subsys_state *css; + char *dead = ""; + + css = &c->memcg_params.memcg->css; + if (!(css->flags & CSS_ONLINE)) + dead = ":dead"; + + memset(&sinfo, 0, sizeof(sinfo)); + get_slabinfo(c, &sinfo); + seq_printf(m, "%-17s %4d%5s %6lu %6lu %6lu %6lu\n", + cache_name(c), css->id, dead, + sinfo.active_objs, sinfo.num_objs, + sinfo.active_slabs, sinfo.num_slabs); + } + } + mutex_unlock(&slab_mutex); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(memcg_slabinfo); + +static int __init memcg_slabinfo_init(void) +{ + debugfs_create_file("memcg_slabinfo", S_IFREG | S_IRUGO, + NULL, NULL, &memcg_slabinfo_fops); + return 0; +} + +late_initcall(memcg_slabinfo_init); +#endif /* CONFIG_DEBUG_FS && CONFIG_MEMCG_KMEM */ #endif /* CONFIG_SLAB || CONFIG_SLUB_DEBUG */ static __always_inline void *__do_krealloc(const void *p, size_t new_size, -- 2.18.1