Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755538Ab3IIT73 (ORCPT ); Mon, 9 Sep 2013 15:59:29 -0400 Received: from gmmr8.centrum.cz ([46.255.227.254]:38545 "EHLO gmmr8.centrum.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754351Ab3IIT7Z (ORCPT ); Mon, 9 Sep 2013 15:59:25 -0400 To: =?utf-8?q?Johannes_Weiner?= Subject: =?utf-8?q?Re=3A_=5Bpatch_0=2F7=5D_improve_memcg_oom_killer_robustness_v2?= Date: Mon, 09 Sep 2013 21:59:17 +0200 From: "azurIt" Cc: =?utf-8?q?Andrew_Morton?= , =?utf-8?q?Michal_Hocko?= , =?utf-8?q?David_Rientjes?= , =?utf-8?q?KAMEZAWA_Hiroyuki?= , =?utf-8?q?KOSAKI_Motohiro?= , , , , , References: <1375549200-19110-1-git-send-email-hannes@cmpxchg.org>, <20130803170831.GB23319@cmpxchg.org>, <20130830215852.3E5D3D66@pobox.sk>, <20130902123802.5B8E8CB1@pobox.sk>, <20130903204850.GA1412@cmpxchg.org>, <20130904101852.58E70042@pobox.sk>, <20130905115430.GB856@cmpxchg.org>, <20130909151010.3A3CBC6A@pobox.sk> <20130909172849.GG856@cmpxchg.org> In-Reply-To: <20130909172849.GG856@cmpxchg.org> X-Mailer: Centrum Email 5.3 X-Priority: 3 X-Original-From: azurit@pobox.sk MIME-Version: 1.0 Message-Id: <20130909215917.96932098@pobox.sk> X-Maser: Georgo 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: 5391 Lines: 104 >On Mon, Sep 09, 2013 at 03:10:10PM +0200, azurIt wrote: >> >Hi azur, >> > >> >On Wed, Sep 04, 2013 at 10:18:52AM +0200, azurIt wrote: >> >> > CC: "Andrew Morton" , "Michal Hocko" , "David Rientjes" , "KAMEZAWA Hiroyuki" , "KOSAKI Motohiro" , linux-mm@kvack.org, cgroups@vger.kernel.org, x86@kernel.org, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org >> >> >Hello azur, >> >> > >> >> >On Mon, Sep 02, 2013 at 12:38:02PM +0200, azurIt wrote: >> >> >> >>Hi azur, >> >> >> >> >> >> >> >>here is the x86-only rollup of the series for 3.2. >> >> >> >> >> >> >> >>Thanks! >> >> >> >>Johannes >> >> >> >>--- >> >> >> > >> >> >> > >> >> >> >Johannes, >> >> >> > >> >> >> >unfortunately, one problem arises: I have (again) cgroup which cannot be deleted :( it's a user who had very high memory usage and was reaching his limit very often. Do you need any info which i can gather now? >> >> > >> >> >Did the OOM killer go off in this group? >> >> > >> >> >Was there a warning in the syslog ("Fixing unhandled memcg OOM >> >> >context")? >> >> >> >> >> >> >> >> Ok, i see this message several times in my syslog logs, one of them is also for this unremovable cgroup (but maybe all of them cannot be removed, should i try?). Example of the log is here (don't know where exactly it starts and ends so here is the full kernel log): >> >> http://watchdog.sk/lkml/oom_syslog.gz >> >There is an unfinished OOM invocation here: >> > >> > Aug 22 13:15:21 server01 kernel: [1251422.715112] Fixing unhandled memcg OOM context set up from: >> > Aug 22 13:15:21 server01 kernel: [1251422.715191] [] T.1154+0x622/0x8f0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715274] [] mem_cgroup_cache_charge+0xbe/0xe0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715357] [] add_to_page_cache_locked+0x4c/0x140 >> > Aug 22 13:15:21 server01 kernel: [1251422.715443] [] add_to_page_cache_lru+0x22/0x50 >> > Aug 22 13:15:21 server01 kernel: [1251422.715526] [] find_or_create_page+0x73/0xb0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715608] [] __getblk+0xea/0x2c0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715692] [] __bread+0x13/0xc0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715774] [] ext3_get_branch+0x98/0x140 >> > Aug 22 13:15:21 server01 kernel: [1251422.715859] [] ext3_get_blocks_handle+0xd7/0xdc0 >> > Aug 22 13:15:21 server01 kernel: [1251422.715942] [] ext3_get_block+0xc4/0x120 >> > Aug 22 13:15:21 server01 kernel: [1251422.716023] [] do_mpage_readpage+0x38a/0x690 >> > Aug 22 13:15:21 server01 kernel: [1251422.716107] [] mpage_readpage+0x4f/0x70 >> > Aug 22 13:15:21 server01 kernel: [1251422.716188] [] ext3_readpage+0x28/0x60 >> > Aug 22 13:15:21 server01 kernel: [1251422.716268] [] filemap_fault+0x308/0x560 >> > Aug 22 13:15:21 server01 kernel: [1251422.716350] [] __do_fault+0x78/0x5a0 >> > Aug 22 13:15:21 server01 kernel: [1251422.716433] [] handle_pte_fault+0x84/0x940 >> > >> >__getblk() has this weird loop where it tries to instantiate the page, >> >frees memory on failure, then retries. If the memcg goes OOM, the OOM >> >path might be entered multiple times and each time leak the memcg >> >reference of the respective previous OOM invocation. >> > >> >There are a few more find_or_create() sites that do not propagate an >> >error and it's incredibly hard to find out whether they are even taken >> >during a page fault. It's not practical to annotate them all with >> >memcg OOM toggles, so let's just catch all OOM contexts at the end of >> >handle_mm_fault() and clear them if !VM_FAULT_OOM instead of treating >> >this like an error. >> > >> >azur, here is a patch on top of your modified 3.2. Note that Michal >> >might be onto something and we are looking at multiple issues here, >> >but the log excert above suggests this fix is required either way. >> >> >> >> >> Johannes, is this still up to date? Thank you. > >No, please use the following on top of 3.2 (i.e. full replacement, not >incremental to what you have): Unfortunately it didn't compile: LD vmlinux.o MODPOST vmlinux.o WARNING: modpost: Found 4924 section mismatch(es). To see full details build your kernel with: 'make CONFIG_DEBUG_SECTION_MISMATCH=y' GEN .version CHK include/generated/compile.h UPD include/generated/compile.h CC init/version.o LD init/built-in.o LD .tmp_vmlinux1 arch/x86/built-in.o: In function `do_page_fault': (.text+0x26a77): undefined reference to `handle_mm_fault' mm/built-in.o: In function `fixup_user_fault': (.text+0x224d3): undefined reference to `handle_mm_fault' mm/built-in.o: In function `__get_user_pages': (.text+0x24a0f): undefined reference to `handle_mm_fault' make: *** [.tmp_vmlinux1] Error 1 -- 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/