ext4 filesystem, SATA drive: (gdb) thread apply all bt
Thread 3 (Thread 0xffff9bffc9a0 (LWP 9015)): #0 0x0000ffffaaa462cc in __GI___sigtimedwait (set=<optimized out>, set@entry=0xaaaae725c070, info=info@entry=0xffff9bffbf18, timeout=0x3ff0000000000001, timeout@entry=0x0) at ../sysdeps/unix/sysv/linux/sigtimedwait.c:42 #1 0x0000ffffaab7dfac in __sigwait (set=set@entry=0xaaaae725c070, sig=sig@entry=0xffff9bffbff4) at ../sysdeps/unix/sysv/linux/sigwait.c:28 #2 0x0000aaaad998a628 in sigwait_compat (opaque=0xaaaae725c070) at util/compatfd.c:36 #3 0x0000aaaad998bce0 in qemu_thread_start (args=<optimized out>) at util/qemu-thread-posix.c:498 #4 0x0000ffffaab73088 in start_thread (arg=0xffffc528531f) at pthread_create.c:463 #5 0x0000ffffaaae34ec in thread_start () at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78 Thread 2 (Thread 0xffffa0e779a0 (LWP 9014)): #0 syscall () at ../sysdeps/unix/sysv/linux/aarch64/syscall.S:38 #1 0x0000aaaad998c9e8 in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at /home/ubuntu/qemu/include/qemu/futex.h:29 #2 qemu_event_wait (ev=ev@entry=0xaaaad9a091c0 <rcu_call_ready_event>) at util/qemu-thread-posix.c:442 #3 0x0000aaaad99a6834 in call_rcu_thread (opaque=<optimized out>) at util/rcu.c:261 #4 0x0000aaaad998bce0 in qemu_thread_start (args=<optimized out>) at util/qemu-thread-posix.c:498 #5 0x0000ffffaab73088 in start_thread (arg=0xffffc528542f) at pthread_create.c:463 #6 0x0000ffffaaae34ec in thread_start () at ../sysdeps/unix/sysv/linux/aarch64/clone.S:78 Thread 1 (Thread 0xffffa0fa8010 (LWP 9013)): #0 0x0000ffffaaada154 in __GI_ppoll (fds=0xaaaae7291dc0, nfds=187650771816320, timeout=<optimized out>, timeout@entry=0x0, sigmask=0xffffc52852e0) at ../sysdeps/unix/sysv/linux/ppoll.c:39 #1 0x0000aaaad9987f00 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/aarch64-linux-gnu/bits/poll2.h:77 #2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at util/qemu-timer.c:322 #3 0x0000aaaad9988f80 in os_host_main_loop_wait (timeout=-1) at util/main-loop.c:233 #4 main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:497 #5 0x0000aaaad98b7a30 in convert_do_copy (s=0xffffc52854e8) at qemu-img.c:1980 #6 img_convert (argc=<optimized out>, argv=<optimized out>) at qemu-img.c:2456 #7 0x0000aaaad98b033c in main (argc=7, argv=<optimized out>) at qemu-img.c:4975 -- You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. https://bugs.launchpad.net/bugs/1805256 Title: qemu-img hangs on high core count ARM system Status in QEMU: New Bug description: On the HiSilicon D06 system - a 96 core NUMA arm64 box - qemu-img frequently hangs (~50% of the time) with this command: qemu-img convert -f qcow2 -O qcow2 /tmp/cloudimg /tmp/cloudimg2 Where "cloudimg" is a standard qcow2 Ubuntu cloud image. This qcow2->qcow2 conversion happens to be something uvtool does every time it fetches images. Once hung, attaching gdb gives the following backtrace: (gdb) bt #0 0x0000ffffae4f8154 in __GI_ppoll (fds=0xaaaae8a67dc0, nfds=187650274213760, timeout=<optimized out>, timeout@entry=0x0, sigmask=0xffffc123b950) at ../sysdeps/unix/sysv/linux/ppoll.c:39 #1 0x0000aaaabbefaf00 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/aarch64-linux-gnu/bits/poll2.h:77 #2 qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at util/qemu-timer.c:322 #3 0x0000aaaabbefbf80 in os_host_main_loop_wait (timeout=-1) at util/main-loop.c:233 #4 main_loop_wait (nonblocking=<optimized out>) at util/main-loop.c:497 #5 0x0000aaaabbe2aa30 in convert_do_copy (s=0xffffc123bb58) at qemu-img.c:1980 #6 img_convert (argc=<optimized out>, argv=<optimized out>) at qemu-img.c:2456 #7 0x0000aaaabbe2333c in main (argc=7, argv=<optimized out>) at qemu-img.c:4975 Reproduced w/ latest QEMU git (@ 53744e0a182) To manage notifications about this bug go to: https://bugs.launchpad.net/qemu/+bug/1805256/+subscriptions