From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Nowoczynski Date: Tue, 17 Mar 2009 15:50:52 -0400 Subject: [Lustre-devel] Deadlock in usocklnd Message-ID: <49BFFF1C.8080203@psc.edu> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org Hi, I've got some code which uses ptlrpc and lnet and a few weeks ago we integrated usocklnd into our environment. This lnd has been working quite well and seems very efficient. The only issue so far is that we're hitting a clear case of deadlock when trying to handle a failed connection. I'm not sure if this code is actually in use by any lustre component as of yet but I thought it best to bring this to your attention. paul (gdb) bt #0 0x00002b3872336888 in __lll_mutex_lock_wait () from /lib64/libpthread.so.0 #1 0x00002b38723328a5 in _L_mutex_lock_107 () from /lib64/libpthread.so.0 #2 0x00002b3872332333 in pthread_mutex_lock () from /lib64/libpthread.so.0 #3 0x000000000049c9f5 in usocklnd_find_or_create_conn (peer=0x2695270, type=0, connp=0x42803d30, tx=0x2aaad46f5d10, zc_ack=0x0, send_immediately=0x42803d2c) at ..//../..//lnet-lite/ulnds/socklnd/conn.c:841 #4 0x00000000004a2701 in usocklnd_send (ni=0x25e1810, private=0x0, lntmsg=0x2aaacca1ace0) at ..//../..//lnet-lite/ulnds/socklnd/usocklnd_cb.c:124 #5 0x000000000048d886 in lnet_ni_send (ni=0x25e1810, msg=0x2aaacca1ace0) at ..//../..//lnet-lite/lnet/lib-move.c:863 #6 0x000000000048dd20 in lnet_post_send_locked (msg=0x2aaacca1ace0, do_send=1) at ..//../..//lnet-lite/lnet/lib-move.c:951 #7 0x000000000048dfb4 in lnet_return_credits_locked (msg=0x2aaacca1ae40) at ..//../..//lnet-lite/lnet/lib-move.c:1108 #8 0x0000000000494230 in lnet_complete_msg_locked (msg=0x2aaacca1ae40) at ..//../..//lnet-lite/lnet/lib-msg.c:143 #9 0x00000000004944f5 in lnet_finalize (ni=0x25e1810, msg=0x2aaacca1ae40, status=-5) at ..//../..//lnet-lite/lnet/lib-msg.c:242 #10 0x000000000049bff8 in usocklnd_destroy_tx (ni=0x25e1810, tx=0x26950c0) at ..//../..//lnet-lite/ulnds/socklnd/conn.c:562 #11 0x000000000049c02d in usocklnd_destroy_txlist (ni=0x25e1810, txlist=0x2693650) at ..//../..//lnet-lite/ulnds/socklnd/conn.c:574 #12 0x000000000049b09c in usocklnd_tear_peer_conn (conn=0x2692550) at ..//../..//lnet-lite/ulnds/socklnd/conn.c:148 #13 0x000000000049f5c8 in usocklnd_process_stale_list (pt_data=0x25e1c98) at ..//../..//lnet-lite/ulnds/socklnd/poll.c:112 #14 0x000000000049f7b2 in usocklnd_poll_thread (arg=0x25e1c98) at ..//../..//lnet-lite/ulnds/socklnd/poll.c:169 #15 0x0000000000450871 in psc_usklndthr_begin (arg=0x25e4370) at ..//../..//psc_fsutil_libs/psc_util/usklndthr.c:16 #16 0x000000000044f000 in _pscthr_begin (arg=0x7fff389980b0) at ..//../..//psc_fsutil_libs/psc_util/thread.c:237 #17 0x00002b38723302f7 in start_thread () from /lib64/libpthread.so.0 #18 0x00002b387281fe3d in clone () from /lib64/libc.so.6 (gdb) up #4 0x00000000004a2701 in usocklnd_send (ni=0x25e1810, private=0x0, lntmsg=0x2aaacca1ace0) at ..//../..//lnet-lite/ulnds/socklnd/usocklnd_cb.c:124 124 rc = usocklnd_find_or_create_conn(peer, type, &conn, tx, NULL, (gdb) print *peer $4 = {up_list = {next = 0x6e1b08, prev = 0x6e1b08}, up_peerid = {nid = 562954416842067, pid = 2147520945}, up_conns = {0x2692550, 0x0, 0x0}, up_ni = 0x25e1810, up_incarnation = 0, up_incrn_is_set = 0, up_refcount = {counter = 3}, up_lock = {__data = {__lock = 2, __count = 0, __owner = 23283, __nusers = 1, __kind = 0, __spins = 0, __list = {__prev = 0x0, __next = 0x0}}, __size = "\002\000\000\000\000\000\000\000?Z\000\000\001", '\0' , __align = 2}, up_errored = 0, up_last_alive = 0} (gdb) ## We're waiting for a lock which we already hold! * 6 Thread 1115703616 (LWP 23283) 0x00002b3872336888 in __lll_mutex_lock_wait () from /lib64/libpthread.so.0