On 01/15/2016 08:30 AM, Christian Borntraeger wrote: > On 01/14/2016 08:56 PM, Tejun Heo wrote: >> Hello, >> >> Thanks a lot for the report and detailed analysis. Can you please >> test whether the following patch fixes the issue? >> >> Thanks. >> > > > Yes, the deadlock is gone and the system is still running. > After some time I had the following WARN in the logs, though. > Not sure yet if that is related. > > [25331.763607] DEBUG_LOCKS_WARN_ON(lock->owner != current) > [25331.763630] ------------[ cut here ]------------ > [25331.763634] WARNING: at kernel/locking/mutex-debug.c:80 > [25331.763637] Modules linked in: nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp iptable_filter ip_tables x_tables bridge stp llc btrfs xor raid6_pq ghash_s390 prng ecb aes_s390 des_s390 des_generic sha512_s390 sha256_s390 sha1_s390 sha_common eadm_sch nfsd auth_rpcgss oid_registry nfs_acl lockd vhost_net tun vhost macvtap macvlan grace sunrpc dm_service_time dm_multipath dm_mod autofs4 > [25331.763708] CPU: 56 PID: 114657 Comm: systemd-udevd Not tainted 4.4.0+ #91 > [25331.763711] task: 000000fadc79de40 ti: 000000f95e7f8000 task.ti: 000000f95e7f8000 > [25331.763715] Krnl PSW : 0404c00180000000 00000000001b7f32 (debug_mutex_unlock+0x16a/0x188) > [25331.763726] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 EA:3 > Krnl GPRS: 0000004c00000037 000000fadc79de40 000000000000002b 0000000000000000 > [25331.763732] 000000000028da3c 0000000000000000 000000f95e7fbf08 000000fab8e10df0 > [25331.763735] 000000000000005c 000000facc0dc000 000000000000005c 000000000033e14a > [25331.763738] 0700000000000000 000000fab8e10df0 00000000001b7f2e 000000f95e7fbc80 > [25331.763746] Krnl Code: 00000000001b7f22: c0200042784c larl %r2,a06fba > 00000000001b7f28: c0e50006ad50 brasl %r14,28d9c8 > #00000000001b7f2e: a7f40001 brc 15,1b7f30 > >00000000001b7f32: a7f4ffe1 brc 15,1b7ef4 > 00000000001b7f36: c03000429c9f larl %r3,a0b874 > 00000000001b7f3c: c0200042783f larl %r2,a06fba > 00000000001b7f42: c0e50006ad43 brasl %r14,28d9c8 > 00000000001b7f48: a7f40001 brc 15,1b7f4a > [25331.763795] Call Trace: > [25331.763798] ([<00000000001b7f2e>] debug_mutex_unlock+0x166/0x188) > [25331.763804] [<0000000000836a08>] __mutex_unlock_slowpath+0xa8/0x190 > [25331.763808] [<000000000033e14a>] seq_read+0x1c2/0x450 > [25331.763813] [<0000000000311e72>] __vfs_read+0x42/0x100 > [25331.763818] [<000000000031284e>] vfs_read+0x76/0x130 > [25331.763821] [<000000000031361e>] SyS_read+0x66/0xd8 > [25331.763826] [<000000000083af06>] system_call+0xd6/0x270 > [25331.763829] [<000003ffae1f19c8>] 0x3ffae1f19c8 > [25331.763831] INFO: lockdep is turned off. > [25331.763833] Last Breaking-Event-Address: > [25331.763836] [<00000000001b7f2e>] debug_mutex_unlock+0x166/0x188 > [25331.763839] ---[ end trace 45177640eb39ef44 ]--- > I restarted the test with panic_on_warn. Hopefully I can get a dump to check which mutex this was. Christian -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
