From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx116.postini.com [74.125.245.116]) by kanga.kvack.org (Postfix) with SMTP id D50E86B0034 for ; Sun, 7 Jul 2013 19:42:26 -0400 (EDT) Subject: =?utf-8?q?Re=3A_=5BPATCH_for_3=2E2=5D_memcg=3A_do_not_trap_chargers_with_full_callstack_on_OOM?= Date: Mon, 08 Jul 2013 01:42:24 +0200 From: "azurIt" References: <20130606160446.GE24115@dhcp22.suse.cz>, <20130606181633.BCC3E02E@pobox.sk>, <20130607131157.GF8117@dhcp22.suse.cz>, <20130617122134.2E072BA8@pobox.sk>, <20130619132614.GC16457@dhcp22.suse.cz>, <20130622220958.D10567A4@pobox.sk>, <20130624201345.GA21822@cmpxchg.org>, <20130628120613.6D6CAD21@pobox.sk>, <20130705181728.GQ17812@cmpxchg.org>, <20130705210246.11D2135A@pobox.sk> <20130705191854.GR17812@cmpxchg.org> In-Reply-To: <20130705191854.GR17812@cmpxchg.org> MIME-Version: 1.0 Message-Id: <20130708014224.50F06960@pobox.sk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: =?utf-8?q?Johannes_Weiner?= Cc: =?utf-8?q?Michal_Hocko?= , linux-kernel@vger.kernel.org, linux-mm@kvack.org, =?utf-8?q?cgroups_mailinglist?= , =?utf-8?q?KAMEZAWA_Hiroyuki?= > CC: "Michal Hocko" , linux-kernel@vger.kernel.org, linux-mm@kvack.org, "cgroups mailinglist" , "KAMEZAWA Hiroyuki" >On Fri, Jul 05, 2013 at 09:02:46PM +0200, azurIt wrote: >> >I looked at your debug messages but could not find anything that would >> >hint at a deadlock. All tasks are stuck in the refrigerator, so I >> >assume you use the freezer cgroup and enabled it somehow? >> >> >> Yes, i'm really using freezer cgroup BUT i was checking if it's not >> doing problems - unfortunately, several days passed from that day >> and now i don't fully remember if i was checking it for both cases >> (unremoveabled cgroups and these freezed processes holding web >> server port). I'm 100% sure i was checking it for unremoveable >> cgroups but not so sure for the other problem (i had to act quickly >> in that case). Are you sure (from stacks) that freezer cgroup was >> enabled there? > >Yeah, all the traces without exception look like this: > >1372089762/23433/stack:[] refrigerator+0x95/0x160 >1372089762/23433/stack:[] get_signal_to_deliver+0x1cb/0x540 >1372089762/23433/stack:[] do_signal+0x6b/0x750 >1372089762/23433/stack:[] do_notify_resume+0x55/0x80 >1372089762/23433/stack:[] int_signal+0x12/0x17 >1372089762/23433/stack:[] 0xffffffffffffffff > >so the freezer was already enabled when you took the backtraces. > >> Btw, what about that other stacks? I mean this file: >> http://watchdog.sk/lkml/memcg-bug-7.tar.gz >> >> It was taken while running the kernel with your patch and from >> cgroup which was under unresolveable OOM (just like my very original >> problem). > >I looked at these traces too, but none of the tasks are stuck in rmdir >or the OOM path. Some /are/ in the page fault path, but they are >happily doing reclaim and don't appear to be stuck. So I'm having a >hard time matching this data to what you otherwise observed. > >However, based on what you reported the most likely explanation for >the continued hangs is the unfinished OOM handling for which I sent >the followup patch for arch/x86/mm/fault.c. > Johannes, today I tested both of your patches but problem with unremovable cgroups, unfortunately, persists. azur -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org