Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758161Ab1DYJRV (ORCPT ); Mon, 25 Apr 2011 05:17:21 -0400 Received: from legolas.restena.lu ([158.64.1.34]:36855 "EHLO legolas.restena.lu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758131Ab1DYJRT convert rfc822-to-8bit (ORCPT ); Mon, 25 Apr 2011 05:17:19 -0400 Date: Mon, 25 Apr 2011 11:17:05 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: Mike Frysinger Cc: KOSAKI Motohiro , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org Subject: Re: 2.6.39-rc4+: Kernel leaking memory during FS scanning, regression? Message-ID: <20110425111705.786ef0c5@neptune.home> In-Reply-To: References: <20110424202158.45578f31@neptune.home> <20110424235928.71af51e0@neptune.home> <20110425114429.266A.A69D9226@jp.fujitsu.com> X-Mailer: Claws Mail 3.7.8 (GTK+ 2.22.1; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6722 Lines: 147 On Mon, 25 April 2011 Mike Frysinger wrote: > On Sun, Apr 24, 2011 at 22:42, KOSAKI Motohiro wrote: > >> On Sun, 24 April 2011 Bruno Prémont wrote: > >> > On an older system I've been running Gentoo's revdep-rebuild to check > >> > for system linking/*.la consistency and after doing most of the work the > >> > system starved more or less, just complaining about stuck tasks now and > >> > then. > >> > Memory usage graph as seen from userspace showed sudden quick increase of > >> > memory usage though only a very few MB were swapped out (c.f. attached RRD > >> > graph). > >> > >> Seems I've hit it once again (though detected before system was fully > >> stalled by trying to reclaim memory without success). > >> > >> This time it was during simple compiling... > >> Gathered info below: > >> > >> /proc/meminfo: > >> MemTotal:         480660 kB > >> MemFree:           64948 kB > >> Buffers:           10304 kB > >> Cached:             6924 kB > >> SwapCached:         4220 kB > >> Active:            11100 kB > >> Inactive:          15732 kB > >> Active(anon):       4732 kB > >> Inactive(anon):     4876 kB > >> Active(file):       6368 kB > >> Inactive(file):    10856 kB > >> Unevictable:          32 kB > >> Mlocked:              32 kB > >> SwapTotal:        524284 kB > >> SwapFree:         456432 kB > >> Dirty:                80 kB > >> Writeback:             0 kB > >> AnonPages:          6268 kB > >> Mapped:             2604 kB > >> Shmem:                 4 kB > >> Slab:             250632 kB > >> SReclaimable:      51144 kB > >> SUnreclaim:       199488 kB   <--- look big as well... > >> KernelStack:      131032 kB   <--- what??? > > > > KernelStack is used 8K bytes per thread. then, your system should have > > 16000 threads. but your ps only showed about 80 processes. > > Hmm... stack leak? > > i might have a similar report for 2.6.39-rc4 (seems to be working fine > in 2.6.38.4), but for embedded Blackfin systems running gdbserver > processes over and over (so lots of short lived forks) > > i wonder if you have a lot of zombies or otherwise unclaimed resources > ? does `ps aux` show anything unusual ? I've not seen anything special (no big amount of threads behind my about 80 processes, even after kernel oom-killed nearly all processes the hogged memory has not been freed. And no, there are no zombies around). Here it seems to happened when I run 2 intensive tasks in parallel, e.g. (re)emerging gimp and running revdep-rebuild -pi in another terminal. This produces a fork rate of about 100-300 per second. Suddenly kmalloc-128 slabs stop being freed and things degrade. Trying to trace some of the kmalloc-128 slab allocations I end up seeing lots of allocations like this: [ 1338.554429] TRACE kmalloc-128 alloc 0xc294ff00 inuse=30 fp=0xc294ff00 [ 1338.554434] Pid: 1573, comm: collectd Tainted: G W 2.6.39-rc4-jupiter-00187-g686c4cb #1 [ 1338.554437] Call Trace: [ 1338.554442] [] trace+0x57/0xa0 [ 1338.554447] [] alloc_debug_processing+0xf3/0x140 [ 1338.554452] [] T.999+0x172/0x1a0 [ 1338.554455] [] ? get_empty_filp+0x58/0xc0 [ 1338.554459] [] ? get_empty_filp+0x58/0xc0 [ 1338.554464] [] kmem_cache_alloc+0xb2/0x100 [ 1338.554468] [] ? path_put+0x15/0x20 [ 1338.554472] [] ? get_empty_filp+0x58/0xc0 [ 1338.554476] [] get_empty_filp+0x58/0xc0 [ 1338.554481] [] path_openat+0x1f/0x320 [ 1338.554485] [] ? __access_remote_vm+0x19e/0x1d0 [ 1338.554490] [] do_filp_open+0x30/0x80 [ 1338.554495] [] ? kmem_cache_alloc+0x90/0x100 [ 1338.554500] [] ? getname_flags+0x28/0xe0 [ 1338.554505] [] ? alloc_fd+0x62/0xe0 [ 1338.554509] [] ? getname_flags+0x61/0xe0 [ 1338.554514] [] do_sys_open+0xed/0x1e0 [ 1338.554519] [] sys_open+0x29/0x40 [ 1338.554524] [] sysenter_do_call+0x12/0x26 [ 1338.556764] TRACE kmalloc-128 alloc 0xc294ff80 inuse=31 fp=0xc294ff80 [ 1338.556774] Pid: 1332, comm: bash Tainted: G W 2.6.39-rc4-jupiter-00187-g686c4cb #1 [ 1338.556779] Call Trace: [ 1338.556794] [] trace+0x57/0xa0 [ 1338.556802] [] alloc_debug_processing+0xf3/0x140 [ 1338.556807] [] T.999+0x172/0x1a0 [ 1338.556812] [] ? get_empty_filp+0x58/0xc0 [ 1338.556817] [] ? get_empty_filp+0x58/0xc0 [ 1338.556821] [] kmem_cache_alloc+0xb2/0x100 [ 1338.556826] [] ? get_empty_filp+0x58/0xc0 [ 1338.556830] [] get_empty_filp+0x58/0xc0 [ 1338.556841] [] ? tty_ldisc_deref+0x8/0x10 [ 1338.556849] [] path_openat+0x1f/0x320 [ 1338.556857] [] ? fbcon_cursor+0xfe/0x180 [ 1338.556863] [] do_filp_open+0x30/0x80 [ 1338.556868] [] ? kmem_cache_alloc+0x90/0x100 [ 1338.556873] [] ? do_vfs_ioctl+0x7e/0x580 [ 1338.556878] [] ? getname_flags+0x28/0xe0 [ 1338.556886] [] ? alloc_fd+0x62/0xe0 [ 1338.556891] [] ? getname_flags+0x61/0xe0 [ 1338.556898] [] do_sys_open+0xed/0x1e0 [ 1338.556903] [] sys_open+0x29/0x40 [ 1338.556913] [] sysenter_do_call+0x12/0x26 Collectd is system monitoring daemon that counts processes, memory usage an much more, reading lots of files under /proc every 10 seconds. Maybe it opens a process related file at a racy moment and thus prevents the 128 slabs and kernel stacks from being released? Replaying the scenario I'm at: Slab: 43112 kB SReclaimable: 25396 kB SUnreclaim: 17716 kB KernelStack: 16432 kB PageTables: 1320 kB with kmalloc-256 55 64 256 16 1 : tunables 0 0 0 : slabdata 4 4 0 kmalloc-128 66656 66656 128 32 1 : tunables 0 0 0 : slabdata 2083 2083 0 kmalloc-64 3902 3904 64 64 1 : tunables 0 0 0 : slabdata 61 61 0 (and compiling process tree now SIGSTOPped in order to have system not starve immediately so I can look around for information) If I resume one of the compiling process trees both KernelStack and slab (kmalloc-128) usage increase quite quickly (and seems to never get down anymore) - probably at same rate as processes get born (no matter when they end). Bruno > -mike -- 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/