[Qemu-devel] [Bug 1824053] Re: Qemu-img convert appears to be stuck on aarch64 host with low probability

[Thomas Huth]

Ok, we can track the bug reported by Dann Frazier in ticket 1805256
instead.

** Bug watch removed: Red Hat Bugzilla #1524770
   https://bugzilla.redhat.com/show_bug.cgi?id=1524770

-- 
You received this bug notification because you are a member of qemu-
devel-ml, which is subscribed to QEMU.
https://bugs.launchpad.net/bugs/1824053

Title:
  Qemu-img convert appears to be stuck on aarch64 host with low
  probability

Status in QEMU:
  Fix Released

Bug description:
  Hi,  I found a problem that qemu-img convert appears to be stuck on
  aarch64 host with low probability.

  The convert command  line is  "qemu-img convert -f qcow2 -O raw
  disk.qcow2 disk.raw ".

  The bt is below:

  Thread 2 (Thread 0x40000b776e50 (LWP 27215)):
  #0  0x000040000a3f2994 in sigtimedwait () from /lib64/libc.so.6
  #1  0x000040000a39c60c in sigwait () from /lib64/libpthread.so.0
  #2  0x0000aaaaaae82610 in sigwait_compat (opaque=0xaaaac5163b00) at 
util/compatfd.c:37
  #3  0x0000aaaaaae85038 in qemu_thread_start (address@hidden) at 
util/qemu_thread_posix.c:496
  #4  0x000040000a3918bc in start_thread () from /lib64/libpthread.so.0
  #5  0x000040000a492b2c in thread_start () from /lib64/libc.so.6

  Thread 1 (Thread 0x40000b573370 (LWP 27214)):
  #0  0x000040000a489020 in ppoll () from /lib64/libc.so.6
  #1  0x0000aaaaaadaefc0 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized 
out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
  #2  qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, 
timeout=<optimized out>) at qemu_timer.c:391
  #3  0x0000aaaaaadae014 in os_host_main_loop_wait (timeout=<optimized out>) at 
main_loop.c:272
  #4  0x0000aaaaaadae190 in main_loop_wait (nonblocking=<optimized out>) at 
main_loop.c:534
  #5  0x0000aaaaaad97be0 in convert_do_copy (s=0xffffdc32eb48) at 
qemu-img.c:1923
  #6  0x0000aaaaaada2d70 in img_convert (argc=<optimized out>, argv=<optimized 
out>) at qemu-img.c:2414
  #7  0x0000aaaaaad99ac4 in main (argc=7, argv=<optimized out>) at 
qemu-img.c:5305

  
  The problem seems to be very similar to the phenomenon described by this 
patch 
(https://resources.ovirt.org/pub/ovirt-4.1/src/qemu-kvm-ev/0025-aio_notify-force-main-loop-wakeup-with-SIGIO-aarch64.patch),
 

  which force main loop wakeup with SIGIO.  But this patch was reverted
  by the patch (http://ovirt.repo.nfrance.com/src/qemu-kvm-ev/kvm-
  Revert-aio_notify-force-main-loop-wakeup-with-SIGIO-.patch).

  The problem still seems to exist in aarch64 host. The qemu version I used is 
2.8.1. The host version is 4.19.28-1.2.108.aarch64.
   Do you have any solutions to fix it?  Thanks for your reply !

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1824053/+subscriptions