Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 29 Nov 2018 05:06:47 -0800
From:   "Paul E. McKenney" <paulmck@linux.ibm.com>
To:     "He, Bo" <bo.he@intel.com>
Cc:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "josh@joshtriplett.org" <josh@joshtriplett.org>,
        "rostedt@goodmis.org" <rostedt@goodmis.org>,
        "mathieu.desnoyers@efficios.com" <mathieu.desnoyers@efficios.com>,
        "jiangshanlai@gmail.com" <jiangshanlai@gmail.com>,
        "Zhang, Jun" <jun.zhang@intel.com>,
        "Xiao, Jin" <jin.xiao@intel.com>,
        "Zhang, Yanmin" <yanmin.zhang@intel.com>
Subject: Re: rcu_preempt caused oom
Reply-To: paulmck@linux.ibm.com
References: <CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX104.ccr.corp.intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CD6925E8781EFD4D8E11882D20FC406D52A11F61@SHSMSX104.ccr.corp.intel.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Message-Id: <20181129130647.GG4170@linux.ibm.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Thu, Nov 29, 2018 at 08:49:35AM +0000, He, Bo wrote:
> Hi, 
>       we test on kernel 4.19.0 on android, after run more than 24 Hours monkey stress test, we see OOM on 1/10 2G memory board, the issue is not seen on the 4.14 kernel.
> we have done some debugs:
> 1. OOM is due to the filp consume too many memory: 300M vs 2G board.
> 2. with the 120s hung task detect, most of the tasks will block at __wait_rcu_gp: wait_for_completion(&rs_array[i].completion);
> [47571.863839] Kernel panic - not syncing: hung_task: blocked tasks
> [47571.875446] CPU: 1 PID: 13626 Comm: FinalizerDaemon Tainted: G     U     O      4.19.0-quilt-2e5dc0ac-gf3f313245eb6 #1
> [47571.887603] Call Trace:
> [47571.890547]  dump_stack+0x70/0xa5
> [47571.894456]  panic+0xe3/0x241
> [47571.897977]  ? wait_for_completion_timeout+0x72/0x1b0
> [47571.903830]  __wait_rcu_gp+0x17b/0x180
> [47571.908226]  synchronize_rcu.part.76+0x38/0x50
> [47571.913393]  ? __call_rcu.constprop.79+0x3a0/0x3a0
> [47571.918948]  ? __bpf_trace_rcu_invoke_callback+0x10/0x10
> [47571.925094]  synchronize_rcu+0x43/0x50
> [47571.929487]  evdev_detach_client+0x59/0x60
> [47571.934264]  evdev_release+0x4e/0xd0
> [47571.938464]  __fput+0xfa/0x1f0
> [47571.942072]  ____fput+0xe/0x10
> [47571.945683]  task_work_run+0x90/0xc0
> [47571.949884]  exit_to_usermode_loop+0x9f/0xb0
> [47571.954855]  do_syscall_64+0xfa/0x110
> [47571.959151]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 3. after enable the rcu trace, we don't see rcu_quiescent_state_report trace in a long time, we see rcu_callback: rcu_preempt will never response with the rcu_invoke_callback.
> [47572.040668]      ps-12388   1d..1 47566097572us : rcu_grace_period: rcu_preempt 23716088 AccWaitCB
> [47572.040707]      ps-12388   1d... 47566097621us : rcu_callback: rcu_preempt rhp=00000000783a728b func=file_free_rcu 4354/82824
> [47572.040734]      ps-12388   1d..1 47566097622us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Startleaf
> [47572.040756]      ps-12388   1d..1 47566097623us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Prestarted
> [47572.040778]      ps-12388   1d..1 47566097623us : rcu_grace_period: rcu_preempt 23716088 AccWaitCB
> [47572.040802]      ps-12388   1d... 47566097674us : rcu_callback: rcu_preempt rhp=0000000042c76521 func=file_free_rcu 4354/82825
> [47572.040824]      ps-12388   1d..1 47566097676us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Startleaf
> [47572.040847]      ps-12388   1d..1 47566097676us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Prestarted
> [47572.040868]      ps-12388   1d..1 47566097676us : rcu_grace_period: rcu_preempt 23716088 AccWaitCB
> [47572.040895]      ps-12388   1d..1 47566097716us : rcu_callback: rcu_preempt rhp=000000005e40fde2 func=avc_node_free 4354/82826
> [47572.040919]      ps-12388   1d..1 47566097735us : rcu_callback: rcu_preempt rhp=00000000f80fe353 func=avc_node_free 4354/82827
> [47572.040943]      ps-12388   1d..1 47566097758us : rcu_callback: rcu_preempt rhp=000000007486f400 func=avc_node_free 4354/82828
> [47572.040967]      ps-12388   1d..1 47566097760us : rcu_callback: rcu_preempt rhp=00000000b87872a8 func=avc_node_free 4354/82829
> [47572.040990]      ps-12388   1d... 47566097789us : rcu_callback: rcu_preempt rhp=000000008c656343 func=file_free_rcu 4354/82830
> [47572.041013]      ps-12388   1d..1 47566097790us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Startleaf
> [47572.041036]      ps-12388   1d..1 47566097790us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Prestarted
> [47572.041057]      ps-12388   1d..1 47566097791us : rcu_grace_period: rcu_preempt 23716088 AccWaitCB
> [47572.041081]      ps-12388   1d... 47566097871us : rcu_callback: rcu_preempt rhp=000000007e6c898c func=file_free_rcu 4354/82831
> [47572.041103]      ps-12388   1d..1 47566097872us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Startleaf
> [47572.041126]      ps-12388   1d..1 47566097872us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Prestarted
> [47572.041147]      ps-12388   1d..1 47566097873us : rcu_grace_period: rcu_preempt 23716088 AccWaitCB
> [47572.041170]      ps-12388   1d... 47566097945us : rcu_callback: rcu_preempt rhp=0000000032f4f174 func=file_free_rcu 4354/82832
> [47572.041193]      ps-12388   1d..1 47566097946us : rcu_future_grace_period: rcu_preempt 23716088 23716092 0 0 3 Startleaf
> 
> Do you have any suggestions to debug the issue?

If you do not already have CONFIG_RCU_BOOST=y set, could you please
rebuild with that?

Could you also please send your .config file?

							Thanx, Paul