On 08/07/14 09:43, Ming Lei wrote: > On Tue, Jul 8, 2014 at 3:19 PM, Christian Borntraeger > <borntrae...@de.ibm.com> wrote: >> Ping. >> >> has anyone seen a similar hang on x86? >> >> >> >> On 07/07/14 13:58, Christian Borntraeger wrote: >>> Folks, >>> >>> with current 2.1-rc0 ( >>> + dataplane: do not free VirtQueueElement in vring_push() >>> + virtio-blk: avoid dataplane VirtIOBlockReq early free >>> + some not-ready yet s390 patches for migration >>> ) >>> >>> I still having issues with dataplane during managedsave (without dataplane >>> everything seems to work fine): >>> >>> With 1 CPU and 1 disk (and some workload, e.g. a simple dd on the disk) I >>> get: >>> >>> >>> Thread 3 (Thread 0x3fff90fd910 (LWP 27218)): >>> #0 0x000003fffcdb7ba0 in __lll_lock_wait () from /lib64/libpthread.so.0 >>> #1 0x000003fffcdbac0c in __pthread_mutex_cond_lock () from >>> /lib64/libpthread.so.0 >>> #2 0x000003fffcdb399a in pthread_cond_wait@@GLIBC_2.3.2 () from >>> /lib64/libpthread.so.0 >>> #3 0x00000000801fff06 in qemu_cond_wait (cond=<optimized out>, >>> mutex=mutex@entry=0x8037f788 <qemu_global_mutex>) at >>> /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:135 >>> #4 0x00000000800472f4 in qemu_kvm_wait_io_event (cpu=<optimized out>) at >>> /home/cborntra/REPOS/qemu/cpus.c:843 >>> #5 qemu_kvm_cpu_thread_fn (arg=0x809ad6b0) at >>> /home/cborntra/REPOS/qemu/cpus.c:879 >>> #6 0x000003fffcdaf412 in start_thread () from /lib64/libpthread.so.0 >>> #7 0x000003fffba350ae in thread_start () from /lib64/libc.so.6 >>> >>> Thread 2 (Thread 0x3fff88fd910 (LWP 27219)): >>> #0 0x000003fffba2a8e0 in ppoll () from /lib64/libc.so.6 >>> #1 0x00000000801af250 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized >>> out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77 >>> #2 qemu_poll_ns (fds=fds@entry=0x3fff40010c0, nfds=nfds@entry=3, >>> timeout=-1) at /home/cborntra/REPOS/qemu/qemu-timer.c:314 >>> #3 0x00000000801b0702 in aio_poll (ctx=0x807f2230, >>> blocking=blocking@entry=true) at /home/cborntra/REPOS/qemu/aio-posix.c:221 >>> #4 0x00000000800be3c4 in iothread_run (opaque=0x807f20d8) at >>> /home/cborntra/REPOS/qemu/iothread.c:41 >>> #5 0x000003fffcdaf412 in start_thread () from /lib64/libpthread.so.0 >>> #6 0x000003fffba350ae in thread_start () from /lib64/libc.so.6 >>> >>> Thread 1 (Thread 0x3fff9c529b0 (LWP 27215)): >>> #0 0x000003fffcdb38f0 in pthread_cond_wait@@GLIBC_2.3.2 () from >>> /lib64/libpthread.so.0 >>> #1 0x00000000801fff06 in qemu_cond_wait (cond=cond@entry=0x807f22c0, >>> mutex=mutex@entry=0x807f2290) at >>> /home/cborntra/REPOS/qemu/util/qemu-thread-posix.c:135 >>> #2 0x0000000080212906 in rfifolock_lock (r=r@entry=0x807f2290) at >>> /home/cborntra/REPOS/qemu/util/rfifolock.c:59 >>> #3 0x000000008019e536 in aio_context_acquire (ctx=ctx@entry=0x807f2230) at >>> /home/cborntra/REPOS/qemu/async.c:295 >>> #4 0x00000000801a34e6 in bdrv_drain_all () at >>> /home/cborntra/REPOS/qemu/block.c:1907 >>> #5 0x0000000080048e24 in do_vm_stop (state=RUN_STATE_PAUSED) at >>> /home/cborntra/REPOS/qemu/cpus.c:538 >>> #6 vm_stop (state=state@entry=RUN_STATE_PAUSED) at >>> /home/cborntra/REPOS/qemu/cpus.c:1221 >>> #7 0x00000000800e6338 in qmp_stop (errp=errp@entry=0x3ffffa9dc00) at >>> /home/cborntra/REPOS/qemu/qmp.c:98 >>> #8 0x00000000800e1314 in qmp_marshal_input_stop (mon=<optimized out>, >>> qdict=<optimized out>, ret=<optimized out>) at qmp-marshal.c:2806 >>> #9 0x000000008004b91a in qmp_call_cmd (cmd=<optimized out>, >>> params=0x8096cf50, mon=0x8080b8a0) at >>> /home/cborntra/REPOS/qemu/monitor.c:5038 >>> #10 handle_qmp_command (parser=<optimized out>, tokens=<optimized out>) at >>> /home/cborntra/REPOS/qemu/monitor.c:5104 >>> #11 0x00000000801faf16 in json_message_process_token (lexer=0x8080b7c0, >>> token=0x808f2610, type=<optimized out>, x=<optimized out>, y=6) at >>> /home/cborntra/REPOS/qemu/qobject/json-streamer.c:87 >>> #12 0x0000000080212bac in json_lexer_feed_char >>> (lexer=lexer@entry=0x8080b7c0, ch=<optimized out>, flush=flush@entry=false) >>> at /home/cborntra/REPOS/qemu/qobject/json-lexer.c:303 >>> #13 0x0000000080212cfe in json_lexer_feed (lexer=0x8080b7c0, >>> buffer=<optimized out>, size=<optimized out>) at >>> /home/cborntra/REPOS/qemu/qobject/json-lexer.c:356 >>> #14 0x00000000801fb10e in json_message_parser_feed (parser=<optimized out>, >>> buffer=<optimized out>, size=<optimized out>) at >>> /home/cborntra/REPOS/qemu/qobject/json-streamer.c:110 >>> #15 0x0000000080049f28 in monitor_control_read (opaque=<optimized out>, >>> buf=<optimized out>, size=<optimized out>) at >>> /home/cborntra/REPOS/qemu/monitor.c:5125 >>> #16 0x00000000800c8636 in qemu_chr_be_write (len=1, buf=0x3ffffa9e010 >>> "}[B\377\373\251\372\b", s=0x807f5af0) at >>> /home/cborntra/REPOS/qemu/qemu-char.c:213 >>> #17 tcp_chr_read (chan=<optimized out>, cond=<optimized out>, >>> opaque=0x807f5af0) at /home/cborntra/REPOS/qemu/qemu-char.c:2690 >>> #18 0x000003fffcc9f05a in g_main_context_dispatch () from >>> /lib64/libglib-2.0.so.0 >>> #19 0x00000000801ae3e0 in glib_pollfds_poll () at >>> /home/cborntra/REPOS/qemu/main-loop.c:190 >>> #20 os_host_main_loop_wait (timeout=<optimized out>) at >>> /home/cborntra/REPOS/qemu/main-loop.c:235 >>> #21 main_loop_wait (nonblocking=<optimized out>) at >>> /home/cborntra/REPOS/qemu/main-loop.c:484 >>> #22 0x00000000800169e2 in main_loop () at >>> /home/cborntra/REPOS/qemu/vl.c:2024 >>> #23 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) >>> at /home/cborntra/REPOS/qemu/vl.c:4551 >>> >>> Now. If aio_poll never returns, we have a deadlock here. >>> To me it looks like, that aio_poll could be called from iothread_run, even >>> if there are no outstanding request. >>> Opinions? > > I have sent out one patch to fix the issue, and the title is > "virtio-blk: data-plane: fix save/set .complete_request in start". > > Please try this patch to see if it fixes your issue.
Yes, I have seen that patch. Unfortunately it does not make a difference for the managedsave case.