Hi, I'm getting the following lockdep warning on my test machine (running reasonably recent kernel from -git):
======================================================= [ INFO: possible circular locking dependency detected ] 2.6.24-rc3-g406f602d-dirty #28 ------------------------------------------------------- quota_nld/3253 is trying to acquire lock: (genl_mutex){--..}, at: [<c02ee382>] ctrl_dumpfamily+0x37/0xea but task is already holding lock: (nlk->cb_mutex){--..}, at: [<c02ead8d>] netlink_dump+0x3a/0x16f which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (nlk->cb_mutex){--..}: [<c0130eff>] __lock_acquire+0xa12/0xbd9 [<c01314a9>] lock_acquire+0x5f/0x78 [<c033b9c7>] mutex_lock_nested+0xff/0x273 [<c02ecb92>] netlink_dump_start+0xcb/0x13b [<c02ee2a2>] genl_rcv_msg+0xa3/0x14c [<c02ebc09>] netlink_rcv_skb+0x30/0x86 [<c02ee4f9>] genl_rcv+0x1e/0x2d [<c02eb9dc>] netlink_unicast+0x19a/0x1f2 [<c02ec5bb>] netlink_sendmsg+0x251/0x25d [<c02d4ecf>] sock_sendmsg+0xcc/0xe5 [<c02d5039>] sys_sendmsg+0x151/0x1af [<c02d5e9f>] sys_socketcall+0x203/0x222 [<c01026be>] sysenter_past_esp+0x5f/0xa5 [<ffffffff>] 0xffffffff -> #0 (genl_mutex){--..}: [<c0130df3>] __lock_acquire+0x906/0xbd9 [<c01314a9>] lock_acquire+0x5f/0x78 [<c033b9c7>] mutex_lock_nested+0xff/0x273 [<c02ee382>] ctrl_dumpfamily+0x37/0xea [<c02eada5>] netlink_dump+0x52/0x16f [<c02ec0f8>] netlink_recvmsg+0x15f/0x21d [<c02d4dea>] sock_recvmsg+0xd6/0xef [<c02d5897>] sys_recvmsg+0xf8/0x188 [<c02d5eb4>] sys_socketcall+0x218/0x222 [<c01026be>] sysenter_past_esp+0x5f/0xa5 [<ffffffff>] 0xffffffff other info that might help us debug this: 1 lock held by quota_nld/3253: #0: (nlk->cb_mutex){--..}, at: [<c02ead8d>] netlink_dump+0x3a/0x16f stack backtrace: [<c0103707>] show_trace_log_lvl+0x1a/0x2f [<c010409a>] show_trace+0x12/0x14 [<c010418c>] dump_stack+0x16/0x18 [<c012f5e1>] print_circular_bug_tail+0x5f/0x68 [<c0130df3>] __lock_acquire+0x906/0xbd9 [<c01314a9>] lock_acquire+0x5f/0x78 [<c033b9c7>] mutex_lock_nested+0xff/0x273 [<c02ee382>] ctrl_dumpfamily+0x37/0xea [<c02eada5>] netlink_dump+0x52/0x16f [<c02ec0f8>] netlink_recvmsg+0x15f/0x21d [<c02d4dea>] sock_recvmsg+0xd6/0xef [<c02d5897>] sys_recvmsg+0xf8/0x188 [<c02d5eb4>] sys_socketcall+0x218/0x222 [<c01026be>] sysenter_past_esp+0x5f/0xa5 ======================= Honza -- Jan Kara <[EMAIL PROTECTED]> SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/