[vserver] RCU Lock in vx_vsi_meminfo Kernel 3.5

From: Linux VServer <uranus.lv_at_gmail.com>
Date: Mon 06 Aug 2012 - 12:16:36 BST
Message-ID: <CADR5UH57ADUwfAmjJXa3D=vHn8u_UHbPux+q09dZeBsN_mKq-w@mail.gmail.com>

Hi list,

currently I test the 3.5 Kernel with LV patch and got the following stacktrace:

Starting vservers of type 'default'...

[ 138.008193]
[ 138.009750] ===============================
[ 138.014077] [ INFO: suspicious RCU usage. ]
[ 138.018357] 3.5.0-vs2.3.4 #2 Not tainted
[ 138.022822] -------------------------------
[ 138.027126] include/linux/cgroup.h:559 suspicious
rcu_dereference_check() usage!
[ 138.034664]
[ 138.034664] other info that might help us debug this:
[ 138.034664]
[ 138.042821]
[ 138.042821] rcu_scheduler_active = 1, debug_locks = 0
[ 138.049456] 1 lock held by rc/13160:
[ 138.053140] #0: (&p->lock){+.+.+.}, at: [<ffffffff8118ec5a>]
seq_read+0x3a/0x460
[ 138.061144]
[ 138.061144] stack backtrace:
[ 138.065641] Pid: 13160, comm: rc Not tainted 3.5.0-vs2.3.4 #2
[ 138.071942] Call Trace:
[ 138.074469] [<ffffffff810acd53>] lockdep_rcu_suspicious+0x103/0x140
[ 138.080935] [<ffffffff8115f88a>] mem_cgroup_from_task+0x8a/0x90
[ 138.087063] [<ffffffff8109a4c5>] vx_vsi_meminfo+0x25/0xb0
[ 138.092654] [<ffffffff8111115b>] si_meminfo+0x7b/0x90
[ 138.097907] [<ffffffff811d9d8a>] meminfo_proc_show+0x2a/0x510
[ 138.103843] [<ffffffff8113349c>] ? vma_adjust+0x4ac/0x520
[ 138.109428] [<ffffffff810ae75a>] ? mark_held_locks+0x7a/0x120
[ 138.115363] [<ffffffff8165c751>] ? __mutex_lock_common+0x281/0x3d0
[ 138.121725] [<ffffffff810aeacd>] ? trace_hardirqs_on_caller+0x10d/0x1a0
[ 138.128550] [<ffffffff8118ec5a>] ? seq_read+0x3a/0x460
[ 138.133906] [<ffffffff8118ef6b>] ? seq_read+0x34b/0x460
[ 138.139332] [<ffffffff81154bcf>] ? kmem_cache_alloc+0x3f/0xd0
[ 138.145299] [<ffffffff8118ed18>] seq_read+0xf8/0x460
[ 138.150496] [<ffffffff8118ec20>] ? seq_lseek+0x100/0x100
[ 138.156005] [<ffffffff811ce8a2>] proc_reg_read+0x82/0xc0
[ 138.161506] [<ffffffff81169cb5>] vfs_read+0xc5/0x190
[ 138.166661] [<ffffffff81169e6c>] sys_read+0x4c/0x90
[ 138.171726] [<ffffffff81666979>] system_call_fastpath+0x16/0x1b

The PID referenced had the following commandline: /bin/sh /etc/init.d/rc 3

~# vserver-info
Versions:
                   Kernel: 3.5.0-vs2.3.4
                   VS-API: 0x00020308
                      VCI: 0x0000000013001f11
             util-vserver: 0.30.216-pre3034; Apr 10 2012, 06:16:38

Features:
                       CC: gcc, gcc (Debian 4.4.5-8) 4.4.5
                 CPPFLAGS: ''
                   CFLAGS: '-g -O2 -std=c99 -Wall -pedantic -W -funit-at-a-time'
               build/host: x86_64-pc-linux-gnu/x86_64-pc-linux-gnu
             Use dietlibc: yes
       Build C++ programs:
       Build C99 programs: yes
           Available APIs: compat,v11,fscompat,v13,net,v21,v22,v23,netv2
            ext2fs Source: e2fsprogs
    syscall(2) invocation: alternative
      vserver(2) syscall#: 236/glibc
               crypto api: nss
          python bindings: yes
   use library versioning: yes

Paths:
                   prefix: /usr
        sysconf-Directory: /etc
            cfg-Directory: /etc/vservers
         initrd-Directory: /etc/init.d
       pkgstate-Directory: /var/run/vservers
          vserver-Rootdir: /vservers

Is this a vanilla issue or vserver related?

Best regards

uranus
Received on Mon Aug 6 12:16:49 2012

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