1. 06 Dec, 2009 1 commit
  2. 30 Nov, 2009 1 commit
    • Pekka Enberg's avatar
      SLAB: Fix lockdep annotations for CPU hotplug · ce79ddc8
      Pekka Enberg authored
      As reported by Paul McKenney:
      
        I am seeing some lockdep complaints in rcutorture runs that include
        frequent CPU-hotplug operations.  The tests are otherwise successful.
        My first thought was to send a patch that gave each array_cache
        structure's ->lock field its own struct lock_class_key, but you already
        have a init_lock_keys() that seems to be intended to deal with this.
      
        ------------------------------------------------------------------------
      
        =============================================
        [ INFO: possible recursive locking detected ]
        2.6.32-rc4-autokern1 #1
        ---------------------------------------------
        syslogd/2908 is trying to acquire lock:
         (&nc->lock){..-...}, at: [<c0000000001407f4>] .kmem_cache_free+0x118/0x2d4
      
        but task is already holding lock:
         (&nc->lock){..-...}, at: [<c0000000001411bc>] .kfree+0x1f0/0x324
      
        other info that might help us debug this:
        3 locks held by syslogd/2908:
         #0:  (&u->readlock){+.+.+.}, at: [<c0000000004556f8>] .unix_dgram_recvmsg+0x70/0x338
         #1:  (&nc->lock){..-...}, at: [<c0000000001411bc>] .kfree+0x1f0/0x324
         #2:  (&parent->list_lock){-.-...}, at: [<c000000000140f64>] .__drain_alien_cache+0x50/0xb8
      
        stack backtrace:
        Call Trace:
        [c0000000e8ccafc0] [c0000000000101e4] .show_stack+0x70/0x184 (unreliable)
        [c0000000e8ccb070] [c0000000000afebc] .validate_chain+0x6ec/0xf58
        [c0000000e8ccb180] [c0000000000b0ff0] .__lock_acquire+0x8c8/0x974
        [c0000000e8ccb280] [c0000000000b2290] .lock_acquire+0x140/0x18c
        [c0000000e8ccb350] [c000000000468df0] ._spin_lock+0x48/0x70
        [c0000000e8ccb3e0] [c0000000001407f4] .kmem_cache_free+0x118/0x2d4
        [c0000000e8ccb4a0] [c000000000140b90] .free_block+0x130/0x1a8
        [c0000000e8ccb540] [c000000000140f94] .__drain_alien_cache+0x80/0xb8
        [c0000000e8ccb5e0] [c0000000001411e0] .kfree+0x214/0x324
        [c0000000e8ccb6a0] [c0000000003ca860] .skb_release_data+0xe8/0x104
        [c0000000e8ccb730] [c0000000003ca2ec] .__kfree_skb+0x20/0xd4
        [c0000000e8ccb7b0] [c0000000003cf2c8] .skb_free_datagram+0x1c/0x5c
        [c0000000e8ccb830] [c00000000045597c] .unix_dgram_recvmsg+0x2f4/0x338
        [c0000000e8ccb920] [c0000000003c0f14] .sock_recvmsg+0xf4/0x13c
        [c0000000e8ccbb30] [c0000000003c28ec] .SyS_recvfrom+0xb4/0x130
        [c0000000e8ccbcb0] [c0000000003bfb78] .sys_recv+0x18/0x2c
        [c0000000e8ccbd20] [c0000000003ed388] .compat_sys_recv+0x14/0x28
        [c0000000e8ccbd90] [c0000000003ee1bc] .compat_sys_socketcall+0x178/0x220
        [c0000000e8ccbe30] [c0000000000085d4] syscall_exit+0x0/0x40
      
      This patch fixes the issue by setting up lockdep annotations during CPU
      hotplug.
      Reported-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Tested-by: default avatarPaul E. McKenney <paulmck@linux.vnet.ibm.com>
      Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
      Cc: Christoph Lameter <cl@linux-foundation.org>
      Signed-off-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
      ce79ddc8
  3. 19 Nov, 2009 9 commits
  4. 18 Nov, 2009 29 commits