Activity log for bug #1805256

Date Who What changed Old value New value Message
2018-11-26 22:53:57 dann frazier bug added bug
2018-12-05 11:20:39 Alex Bennée tags qemu-img
2019-04-15 22:25:55 dann frazier qemu: status New Confirmed
2019-04-15 23:37:35 dann frazier bug watch added https://bugzilla.redhat.com/show_bug.cgi?id=1524770
2019-04-15 23:37:54 dann frazier bug added subscriber Ike Panhc
2019-06-05 16:16:14 dann frazier bug task added qemu (Ubuntu)
2019-06-05 16:16:24 dann frazier qemu (Ubuntu): status New Confirmed
2019-09-05 15:03:50 Rafael David Tinoco qemu (Ubuntu): status Confirmed In Progress
2019-09-05 15:03:53 Rafael David Tinoco qemu (Ubuntu): assignee Rafael David Tinoco (rafaeldtinoco)
2019-09-05 15:03:56 Rafael David Tinoco qemu (Ubuntu): importance Undecided Medium
2019-09-10 01:28:48 Rafael David Tinoco bug added subscriber Canonical Server Team
2019-09-10 01:28:55 Rafael David Tinoco bug added subscriber Christian Ehrhardt 
2019-09-10 18:15:40 Rafael David Tinoco summary qemu-img hangs on high core count ARM system qemu-img hangs on rcu_call_ready_event logic in Aarch64 when converting images
2019-09-10 18:15:54 Rafael David Tinoco qemu: status Confirmed In Progress
2019-09-10 18:15:57 Rafael David Tinoco qemu: assignee Rafael David Tinoco (rafaeldtinoco)
2019-09-11 11:19:48 Rafael David Tinoco 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) Command: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- [ Original 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)
2019-09-11 11:20:10 Rafael David Tinoco description Command: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- [ Original 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) Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- [ Original 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)
2019-09-11 19:23:21 Rafael David Tinoco nominated for series Ubuntu Ff-series
2019-09-11 19:23:21 Rafael David Tinoco bug task added qemu (Ubuntu Ff-series)
2019-09-11 19:23:21 Rafael David Tinoco nominated for series Ubuntu Bionic
2019-09-11 19:23:21 Rafael David Tinoco bug task added qemu (Ubuntu Bionic)
2019-09-11 19:23:21 Rafael David Tinoco nominated for series Ubuntu Eoan
2019-09-11 19:23:21 Rafael David Tinoco bug task added qemu (Ubuntu Eoan)
2019-09-11 19:23:21 Rafael David Tinoco nominated for series Ubuntu Disco
2019-09-11 19:23:21 Rafael David Tinoco bug task added qemu (Ubuntu Disco)
2019-10-02 11:02:52 Jan Glauber attachment added aio-posix.tar.xz https://bugs.launchpad.net/qemu/+bug/1805256/+attachment/5293619/+files/aio-posix.tar.xz
2019-10-03 12:28:50 Rafael David Tinoco bug watch added https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65697
2019-10-03 12:29:29 Rafael David Tinoco qemu (Ubuntu Disco): importance Undecided Medium
2019-10-03 12:29:31 Rafael David Tinoco qemu (Ubuntu Bionic): importance Undecided Medium
2019-10-03 12:29:33 Rafael David Tinoco qemu (Ubuntu Ff-series): importance Undecided Medium
2019-10-03 21:35:01 dann frazier bug task added kunpeng920
2019-12-13 14:24:54 dann frazier kunpeng920: status New Confirmed
2019-12-13 14:25:03 dann frazier qemu (Ubuntu Bionic): status New Confirmed
2019-12-13 14:25:06 dann frazier qemu (Ubuntu Disco): status New Confirmed
2019-12-13 14:25:10 dann frazier qemu (Ubuntu Focal): status New Confirmed
2019-12-18 14:52:52 dann frazier attachment added comment-34-ported-to-upstream.patch https://bugs.launchpad.net/qemu/+bug/1805256/+attachment/5313631/+files/comment-34-ported-to-upstream.patch
2019-12-18 16:21:29 Ubuntu Foundations Team Bug Bot tags qemu-img patch qemu-img
2019-12-26 02:35:55 dlw bug added subscriber dlw
2020-02-13 08:41:19 Ike Panhc tags patch qemu-img ikeradar patch qemu-img
2020-02-13 08:42:47 Andrew Cloke kunpeng920: status Confirmed Incomplete
2020-02-13 08:42:50 Andrew Cloke qemu (Ubuntu Bionic): status Confirmed Incomplete
2020-02-13 08:42:52 Andrew Cloke qemu (Ubuntu Disco): status Confirmed Incomplete
2020-02-13 08:42:56 Andrew Cloke qemu (Ubuntu Eoan): status In Progress Incomplete
2020-02-13 08:42:59 Andrew Cloke qemu (Ubuntu Focal): status Confirmed Incomplete
2020-04-15 02:47:27 Rafael David Tinoco qemu (Ubuntu Eoan): assignee Rafael David Tinoco (rafaeldtinoco)
2020-04-15 02:48:17 Rafael David Tinoco qemu: assignee Rafael David Tinoco (rafaeldtinoco)
2020-05-05 15:02:29 Ike Panhc kunpeng920: status Incomplete Triaged
2020-05-05 15:02:45 Ike Panhc kunpeng920: assignee Ike Panhc (ikepanhc)
2020-05-05 15:03:03 Ike Panhc nominated for series kunpeng920/upstream-kernel
2020-05-05 15:03:03 Ike Panhc bug task added kunpeng920/upstream-kernel
2020-05-05 15:03:03 Ike Panhc nominated for series kunpeng920/ubuntu-20.04
2020-05-05 15:03:03 Ike Panhc bug task added kunpeng920/ubuntu-20.04
2020-05-05 15:03:03 Ike Panhc nominated for series kunpeng920/ubuntu-19.10
2020-05-05 15:03:03 Ike Panhc bug task added kunpeng920/ubuntu-19.10
2020-05-05 15:03:03 Ike Panhc nominated for series kunpeng920/ubuntu-18.04
2020-05-05 15:03:03 Ike Panhc bug task added kunpeng920/ubuntu-18.04
2020-05-05 15:03:03 Ike Panhc nominated for series kunpeng920/ubuntu-18.04-hwe
2020-05-05 15:03:03 Ike Panhc bug task added kunpeng920/ubuntu-18.04-hwe
2020-05-05 15:03:24 Ike Panhc kunpeng920/upstream-kernel: status New Fix Committed
2020-05-06 13:08:14 Rafael David Tinoco qemu (Ubuntu): assignee Rafael David Tinoco (rafaeldtinoco)
2020-05-06 13:08:26 Rafael David Tinoco qemu: status In Progress Fix Released
2020-05-06 13:08:59 Rafael David Tinoco qemu (Ubuntu Focal): status Incomplete In Progress
2020-05-06 13:09:10 Rafael David Tinoco qemu (Ubuntu Eoan): status Incomplete In Progress
2020-05-06 13:09:25 Rafael David Tinoco qemu (Ubuntu Disco): status Incomplete In Progress
2020-05-06 13:09:38 Rafael David Tinoco qemu (Ubuntu Bionic): status Incomplete In Progress
2020-05-06 13:09:56 Rafael David Tinoco qemu (Ubuntu): status Incomplete In Progress
2020-05-06 13:23:06 Rafael David Tinoco description Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- [ Original 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) [Impact] * QEMU locking primitives might face a race condition in QEMU Async I/O bottom halves scheduling. This leads to a dead lock making either QEMU or one of its tools to hang indefinitely. [Test Case] * qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs in Aarch64. [Regression Potential] * This is a change to a core part of QEMU: The AIO scheduling. It works like a "kernel" scheduler, whereas kernel schedules OS tasks, the QEMU AIO code is responsible to schedule QEMU coroutines or event listeners callbacks. * There was a long discussion upstream about primitives and Aarch64. After quite sometime Paolo released this patch and it solves the issue. Tested platforms were: amd64 and aarch64 based on his commit log. * Christian suggests that this fix stay little longer in -proposed to make sure it won't cause any regressions. [Other Info] * Original Description bellow: Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- 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)
2020-05-06 15:45:56 Ike Panhc kunpeng920/ubuntu-18.04: status New Triaged
2020-05-06 15:45:56 Ike Panhc kunpeng920/ubuntu-18.04: assignee Ike Panhc (ikepanhc)
2020-05-06 15:46:15 Ike Panhc kunpeng920/ubuntu-18.04-hwe: status New Triaged
2020-05-06 15:46:15 Ike Panhc kunpeng920/ubuntu-18.04-hwe: assignee Ike Panhc (ikepanhc)
2020-05-06 15:46:25 Ike Panhc kunpeng920/ubuntu-19.10: status New Triaged
2020-05-06 15:46:25 Ike Panhc kunpeng920/ubuntu-19.10: assignee Ike Panhc (ikepanhc)
2020-05-06 15:46:35 Ike Panhc kunpeng920/ubuntu-20.04: status New Triaged
2020-05-06 15:46:35 Ike Panhc kunpeng920/ubuntu-20.04: assignee Ike Panhc (ikepanhc)
2020-05-06 16:42:49 dann frazier description [Impact] * QEMU locking primitives might face a race condition in QEMU Async I/O bottom halves scheduling. This leads to a dead lock making either QEMU or one of its tools to hang indefinitely. [Test Case] * qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs in Aarch64. [Regression Potential] * This is a change to a core part of QEMU: The AIO scheduling. It works like a "kernel" scheduler, whereas kernel schedules OS tasks, the QEMU AIO code is responsible to schedule QEMU coroutines or event listeners callbacks. * There was a long discussion upstream about primitives and Aarch64. After quite sometime Paolo released this patch and it solves the issue. Tested platforms were: amd64 and aarch64 based on his commit log. * Christian suggests that this fix stay little longer in -proposed to make sure it won't cause any regressions. [Other Info] * Original Description bellow: Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- 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) [Impact] * QEMU locking primitives might face a race condition in QEMU Async I/O bottom halves scheduling. This leads to a dead lock making either QEMU or one of its tools to hang indefinitely. [Test Case] * qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs in Aarch64. [Regression Potential] * This is a change to a core part of QEMU: The AIO scheduling. It works like a "kernel" scheduler, whereas kernel schedules OS tasks, the QEMU AIO code is responsible to schedule QEMU coroutines or event listeners callbacks. * There was a long discussion upstream about primitives and Aarch64. After quite sometime Paolo released this patch and it solves the issue. Tested platforms were: amd64 and aarch64 based on his commit log. * Christian suggests that this fix stay little longer in -proposed to make sure it won't cause any regressions. * dannf suggests we also check for performance regressions; e.g. how long it takes to convert a cloud image on high-core systems. [Other Info]  * Original Description bellow: Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- 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)
2020-05-06 19:04:22 Launchpad Janitor merge proposal linked https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/qemu/+git/qemu/+merge/383530
2020-05-06 19:06:08 Philippe Mathieu-Daudé bug added subscriber Stefan Hajnoczi
2020-05-06 21:10:06 Launchpad Janitor merge proposal linked https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/qemu/+git/qemu/+merge/383545
2020-05-06 21:44:13 Launchpad Janitor merge proposal linked https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/qemu/+git/qemu/+merge/383551
2020-05-07 03:37:34 Launchpad Janitor merge proposal linked https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/qemu/+git/qemu/+merge/383566
2020-05-14 08:05:17 Andrew Cloke kunpeng920: status Triaged In Progress
2020-05-27 04:55:20 Christian Ehrhardt  bug task deleted qemu (Ubuntu Disco)
2020-05-29 07:55:40 Launchpad Janitor qemu (Ubuntu): status In Progress Fix Released
2020-06-02 22:44:57 Brian Murray tags ikeradar patch qemu-img block-proposed-focal ikeradar patch qemu-img
2020-06-02 22:45:15 Brian Murray qemu (Ubuntu Focal): status In Progress Fix Committed
2020-06-02 22:45:17 Brian Murray bug added subscriber Ubuntu Stable Release Updates Team
2020-06-02 22:45:20 Brian Murray bug added subscriber SRU Verification
2020-06-02 22:45:30 Brian Murray tags block-proposed-focal ikeradar patch qemu-img block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-focal
2020-06-02 22:49:01 Brian Murray qemu (Ubuntu Eoan): status In Progress Fix Committed
2020-06-02 22:49:10 Brian Murray tags block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-focal block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal
2020-06-02 22:49:47 Brian Murray tags block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal
2020-06-02 22:54:23 Brian Murray qemu (Ubuntu Bionic): status In Progress Fix Committed
2020-06-02 22:54:32 Brian Murray tags block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-bionic verification-needed-eoan verification-needed-focal
2020-06-02 22:55:05 Brian Murray tags block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-bionic verification-needed-eoan verification-needed-focal block-proposed-bionic block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal
2020-06-03 06:36:24 Ike Panhc tags block-proposed-bionic block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-needed verification-needed-eoan verification-needed-focal block-proposed-bionic block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-done-bionic verification-done-eoan verification-done-focal
2020-06-03 06:37:09 Ike Panhc kunpeng920/ubuntu-18.04: status Triaged In Progress
2020-06-03 06:37:09 Ike Panhc kunpeng920/ubuntu-18.04: assignee Ike Panhc (ikepanhc)
2020-06-03 06:37:22 Ike Panhc kunpeng920: assignee Ike Panhc (ikepanhc)
2020-06-03 06:37:33 Ike Panhc kunpeng920/ubuntu-18.04-hwe: status Triaged In Progress
2020-06-03 06:37:33 Ike Panhc kunpeng920/ubuntu-18.04-hwe: assignee Ike Panhc (ikepanhc)
2020-06-03 06:37:51 Ike Panhc kunpeng920/ubuntu-19.10: status Triaged In Progress
2020-06-03 06:37:51 Ike Panhc kunpeng920/ubuntu-19.10: assignee Ike Panhc (ikepanhc)
2020-06-03 06:38:02 Ike Panhc kunpeng920/ubuntu-20.04: status Triaged In Progress
2020-06-03 06:38:02 Ike Panhc kunpeng920/ubuntu-20.04: assignee Ike Panhc (ikepanhc)
2020-06-03 06:38:22 Ike Panhc kunpeng920/upstream-kernel: status Fix Committed Invalid
2020-06-11 08:04:02 Andrew Cloke kunpeng920/ubuntu-18.04: status In Progress Fix Committed
2020-06-11 08:04:17 Andrew Cloke kunpeng920/ubuntu-18.04-hwe: status In Progress Fix Committed
2020-06-11 08:04:27 Andrew Cloke kunpeng920/ubuntu-19.10: status In Progress Fix Committed
2020-06-11 08:04:39 Andrew Cloke kunpeng920/ubuntu-20.04: status In Progress Fix Committed
2020-06-11 08:04:49 Andrew Cloke kunpeng920: status In Progress Fix Committed
2020-06-17 05:17:01 Christian Ehrhardt  tags block-proposed-bionic block-proposed-eoan block-proposed-focal ikeradar patch qemu-img verification-done-bionic verification-done-eoan verification-done-focal ikeradar patch qemu-img verification-done-bionic verification-done-eoan verification-done-focal
2020-06-18 09:23:27 Łukasz Zemczak removed subscriber Ubuntu Stable Release Updates Team
2020-06-18 09:23:26 Launchpad Janitor qemu (Ubuntu Focal): status Fix Committed Fix Released
2020-06-18 09:38:29 Launchpad Janitor qemu (Ubuntu Eoan): status Fix Committed Fix Released
2020-06-18 09:39:05 Launchpad Janitor qemu (Ubuntu Bionic): status Fix Committed Fix Released
2020-06-18 10:27:36 Andrew Cloke kunpeng920/ubuntu-20.04: status Fix Committed Fix Released
2020-06-18 10:27:57 Andrew Cloke kunpeng920/ubuntu-19.10: status Fix Committed Fix Released
2020-06-18 10:28:23 Andrew Cloke kunpeng920/ubuntu-18.04-hwe: status Fix Committed Fix Released
2020-06-18 10:28:33 Andrew Cloke kunpeng920/ubuntu-18.04: status Fix Committed Fix Released
2020-06-18 10:28:43 Andrew Cloke kunpeng920: status Fix Committed Fix Released
2020-06-30 06:53:57 Christian Ehrhardt  qemu (Ubuntu Bionic): status Fix Released Triaged
2020-06-30 06:55:07 Christian Ehrhardt  qemu (Ubuntu Bionic): assignee Rafael David Tinoco (rafaeldtinoco)
2020-07-01 07:00:44 Ike Panhc kunpeng920/ubuntu-18.04: status Fix Released Triaged
2020-07-01 07:00:59 Ike Panhc kunpeng920/ubuntu-18.04-hwe: status Fix Released Triaged
2020-07-01 07:02:15 Ike Panhc kunpeng920: status Fix Released Triaged
2020-07-12 13:16:31 Rafael David Tinoco qemu (Ubuntu Bionic): status Triaged In Progress
2020-07-13 03:59:59 Launchpad Janitor merge proposal linked https://code.launchpad.net/~rafaeldtinoco/ubuntu/+source/qemu/+git/qemu/+merge/387269
2020-07-21 20:02:38 Rafael David Tinoco bug watch added https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=890446
2020-07-31 18:51:30 Rafael David Tinoco description [Impact] * QEMU locking primitives might face a race condition in QEMU Async I/O bottom halves scheduling. This leads to a dead lock making either QEMU or one of its tools to hang indefinitely. [Test Case] * qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs in Aarch64. [Regression Potential] * This is a change to a core part of QEMU: The AIO scheduling. It works like a "kernel" scheduler, whereas kernel schedules OS tasks, the QEMU AIO code is responsible to schedule QEMU coroutines or event listeners callbacks. * There was a long discussion upstream about primitives and Aarch64. After quite sometime Paolo released this patch and it solves the issue. Tested platforms were: amd64 and aarch64 based on his commit log. * Christian suggests that this fix stay little longer in -proposed to make sure it won't cause any regressions. * dannf suggests we also check for performance regressions; e.g. how long it takes to convert a cloud image on high-core systems. [Other Info]  * Original Description bellow: Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- 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) SRU TEAM REVIEWER: This has already been SRUed for Focal, Eoan and Bionic. Unfortunately the Bionic SRU did not work and we had to reverse the change. Since then we had another update and now I'm retrying the SRU. After discussing with @paelzer (and @dannf as a reviewer) extensively, Christian and I agreed that we should scope this SRU as Aarch64 only AND I was much, much more conservative in question of what is being changed in the AIO qemu code. New code has been tested against the initial Test Case and the new one, regressed for Bionic. More information (about tests and discussion) can be found in the MR at ~rafaeldtinoco/ubuntu/+source/qemu:lp1805256-bionic-refix BIONIC REGRESSION BUG: https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1885419 [Impact] * QEMU locking primitives might face a race condition in QEMU Async I/O bottom halves scheduling. This leads to a dead lock making either QEMU or one of its tools to hang indefinitely. [Test Case] INITIAL * qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs in Aarch64. [Regression Potential] * This is a change to a core part of QEMU: The AIO scheduling. It works like a "kernel" scheduler, whereas kernel schedules OS tasks, the QEMU AIO code is responsible to schedule QEMU coroutines or event listeners callbacks. * There was a long discussion upstream about primitives and Aarch64. After quite sometime Paolo released this patch and it solves the issue. Tested platforms were: amd64 and aarch64 based on his commit log. * Christian suggests that this fix stay little longer in -proposed to make sure it won't cause any regressions. * dannf suggests we also check for performance regressions; e.g. how long it takes to convert a cloud image on high-core systems. BIONIC REGRESSED ISSUE https://bugs.launchpad.net/ubuntu/+source/qemu/+bug/1885419 [Other Info]  * Original Description bellow: Command: qemu-img convert -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Hangs indefinitely approximately 30% of the runs. ---- Workaround: qemu-img convert -m 1 -f qcow2 -O qcow2 ./disk01.qcow2 ./output.qcow2 Run "qemu-img convert" with "a single coroutine" to avoid this issue. ---- (gdb) thread 1 ... (gdb) bt #0 0x0000ffffbf1ad81c in __GI_ppoll #1 0x0000aaaaaabcf73c in ppoll #2 qemu_poll_ns #3 0x0000aaaaaabd0764 in os_host_main_loop_wait #4 main_loop_wait ... (gdb) thread 2 ... (gdb) bt #0 syscall () #1 0x0000aaaaaabd41cc in qemu_futex_wait #2 qemu_event_wait (ev=ev@entry=0xaaaaaac86ce8 <rcu_call_ready_event>) #3 0x0000aaaaaabed05c in call_rcu_thread #4 0x0000aaaaaabd34c8 in qemu_thread_start #5 0x0000ffffbf25c880 in start_thread #6 0x0000ffffbf1b6b9c in thread_start () (gdb) thread 3 ... (gdb) bt #0 0x0000ffffbf11aa20 in __GI___sigtimedwait #1 0x0000ffffbf2671b4 in __sigwait #2 0x0000aaaaaabd1ddc in sigwait_compat #3 0x0000aaaaaabd34c8 in qemu_thread_start #4 0x0000ffffbf25c880 in start_thread #5 0x0000ffffbf1b6b9c in thread_start ---- (gdb) run Starting program: /usr/bin/qemu-img convert -f qcow2 -O qcow2 ./disk01.ext4.qcow2 ./output.qcow2 [New Thread 0xffffbec5ad90 (LWP 72839)] [New Thread 0xffffbe459d90 (LWP 72840)] [New Thread 0xffffbdb57d90 (LWP 72841)] [New Thread 0xffffacac9d90 (LWP 72859)] [New Thread 0xffffa7ffed90 (LWP 72860)] [New Thread 0xffffa77fdd90 (LWP 72861)] [New Thread 0xffffa6ffcd90 (LWP 72862)] [New Thread 0xffffa67fbd90 (LWP 72863)] [New Thread 0xffffa5ffad90 (LWP 72864)] [Thread 0xffffa5ffad90 (LWP 72864) exited] [Thread 0xffffa6ffcd90 (LWP 72862) exited] [Thread 0xffffa77fdd90 (LWP 72861) exited] [Thread 0xffffbdb57d90 (LWP 72841) exited] [Thread 0xffffa67fbd90 (LWP 72863) exited] [Thread 0xffffacac9d90 (LWP 72859) exited] [Thread 0xffffa7ffed90 (LWP 72860) exited] <HUNG w/ 3 threads in the stack trace showed before> """ All the tasks left are blocked in a system call, so no task left to call qemu_futex_wake() to unblock thread #2 (in futex()), which would unblock thread #1 (doing poll() in a pipe with thread #2). Those 7 threads exit before disk conversion is complete (sometimes in the beginning, sometimes at the end). ---- 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)
2020-07-31 21:41:16 Rafael David Tinoco qemu (Ubuntu Bionic): assignee Rafael David Tinoco (rafaeldtinoco)
2020-08-07 09:53:40 Timo Aaltonen qemu (Ubuntu Bionic): status In Progress Fix Committed
2020-08-07 09:53:43 Timo Aaltonen bug added subscriber Ubuntu Stable Release Updates Team
2020-08-07 09:53:50 Timo Aaltonen tags ikeradar patch qemu-img verification-done-bionic verification-done-eoan verification-done-focal ikeradar patch qemu-img verification-done-eoan verification-done-focal verification-needed verification-needed-bionic
2020-08-07 20:12:35 dann frazier tags ikeradar patch qemu-img verification-done-eoan verification-done-focal verification-needed verification-needed-bionic ikeradar patch qemu-img verification-done verification-done-bionic verification-done-eoan verification-done-focal
2020-08-14 19:49:32 dann frazier kunpeng920/ubuntu-18.04-hwe: status Triaged Fix Committed
2020-08-14 19:49:43 dann frazier kunpeng920/ubuntu-18.04: status Triaged Fix Committed
2020-08-14 19:49:53 dann frazier kunpeng920: status Triaged Fix Committed
2020-08-19 16:36:32 Launchpad Janitor qemu (Ubuntu Bionic): status Fix Committed Fix Released
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-10756
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-12829
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13253
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13361
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13362
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13659
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13754
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-13765
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-15863
2020-08-19 16:36:32 Launchpad Janitor cve linked 2020-16092
2020-08-19 17:16:01 Andrew Cloke kunpeng920/ubuntu-18.04: status Fix Committed Fix Released
2020-08-19 17:16:26 Andrew Cloke bug task deleted kunpeng920/ubuntu-18.04-hwe
2020-08-19 17:16:39 Andrew Cloke kunpeng920: status Fix Committed Fix Released