From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751475AbdJFH7E (ORCPT ); Fri, 6 Oct 2017 03:59:04 -0400 Received: from mx2.suse.de ([195.135.220.15]:57168 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750815AbdJFH7C (ORCPT ); Fri, 6 Oct 2017 03:59:02 -0400 Date: Fri, 6 Oct 2017 09:59:00 +0200 From: Michal Hocko To: Shakeel Butt Cc: Alexander Viro , Vladimir Davydov , Greg Thelen , Andrew Morton , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fs, mm: account filp and names caches to kmemcg Message-ID: <20171006075900.icqjx5rr7hctn3zd@dhcp22.suse.cz> References: <20171005222144.123797-1-shakeelb@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171005222144.123797-1-shakeelb@google.com> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu 05-10-17 15:21:44, Shakeel Butt wrote: > The allocations from filp and names kmem caches can be directly > triggered by user space applications. A buggy application can > consume a significant amount of unaccounted system memory. Though > we have not noticed such buggy applications in our production > but upon close inspection, we found that a lot of machines spend > very significant amount of memory on these caches. So, these > caches should be accounted to kmemcg. > > Signed-off-by: Shakeel Butt > --- > fs/dcache.c | 2 +- > fs/file_table.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/dcache.c b/fs/dcache.c > index f90141387f01..fb3449161063 100644 > --- a/fs/dcache.c > +++ b/fs/dcache.c > @@ -3642,7 +3642,7 @@ void __init vfs_caches_init_early(void) > void __init vfs_caches_init(void) > { > names_cachep = kmem_cache_create("names_cache", PATH_MAX, 0, > - SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); > + SLAB_HWCACHE_ALIGN|SLAB_PANIC|SLAB_ACCOUNT, NULL); I might be wrong but isn't name cache only holding temporary objects used for path resolution which are not stored anywhere? > > dcache_init(); > inode_init(); > diff --git a/fs/file_table.c b/fs/file_table.c > index 61517f57f8ef..567888cdf7d3 100644 > --- a/fs/file_table.c > +++ b/fs/file_table.c > @@ -312,7 +312,7 @@ void put_filp(struct file *file) > void __init files_init(void) > { > filp_cachep = kmem_cache_create("filp", sizeof(struct file), 0, > - SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL); > + SLAB_HWCACHE_ALIGN | SLAB_PANIC | SLAB_ACCOUNT, NULL); > percpu_counter_init(&nr_files, 0, GFP_KERNEL); > } Don't we have a limit for the maximum number of open files? -- Michal Hocko SUSE Labs