Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754961Ab2BCXMc (ORCPT ); Fri, 3 Feb 2012 18:12:32 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:51822 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753951Ab2BCXMb (ORCPT ); Fri, 3 Feb 2012 18:12:31 -0500 Date: Fri, 3 Feb 2012 15:12:18 -0800 From: Andrew Morton To: Johannes Stezenbach Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Thomas Gleixner Subject: Re: huge debug_objects_cache. swapping but 25% mem free Message-Id: <20120203151218.59ceb1c1.akpm@linux-foundation.org> In-Reply-To: <20120201182932.GA15518@sig21.net> References: <20120130154048.GA421@sig21.net> <20120201182932.GA15518@sig21.net> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1954 Lines: 49 On Wed, 1 Feb 2012 19:29:32 +0100 Johannes Stezenbach wrote: > On Mon, Jan 30, 2012 at 04:40:48PM +0100, Johannes Stezenbach wrote: > > > > According to slabtop debug_objects_cache eats half the > > memory, is this expected? The Kconfig help text does not > > suggest it. > > FWIW, today after running full backup using rsync: > > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME > 4025450 4025447 99% 0.36K 183977 22 1471816K debug_objects_cache > 170266 87241 51% 1.74K 9645 18 308640K ext3_inode_cache > 54855 40215 73% 0.58K 2034 27 32544K dentry > 38124 12474 32% 0.42K 2119 18 16952K buffer_head > 17794 17464 98% 0.51K 574 31 9184K sysfs_dir_cache > 11434 8494 74% 0.87K 713 18 11408K radix_tree_node > 11400 5570 48% 0.38K 570 20 4560K kmalloc-64 > > /sys/kernel/debug/debug_objects/stats: > max_chain :870 > warnings :0 > fixups :0 > pool_free :258 > pool_min_free :252 > pool_used :4025193 > pool_max_used :4025195 > > > then after "echo 3 >/proc/sys/vm/drop_caches": > > OBJS ACTIVE USE OBJ SIZE SLABS OBJ/SLAB CACHE SIZE NAME > 4030488 4030485 99% 0.36K 184206 22 1473648K debug_objects_cache > 17955 9071 50% 0.58K 665 27 10640K dentry > 17763 17455 98% 0.51K 573 31 9168K sysfs_dir_cache > 9408 9156 97% 0.33K 392 24 3136K kmalloc-8 > > > I'm still not sure if this is normal behaviour of DEBUG_OBJECTS or a bug? Bug. It appears that you hadn't been using CONFIG_DEBUG_OBJECTS before 3.2 so we don't know if it is a regression. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/