Re: [Qemu-ppc] [PATCH v7 00/73] per-CPU locks

[Richard Henderson]

On 3/4/19 10:17 AM, Emilio G. Cota wrote:
> v6: https://lists.gnu.org/archive/html/qemu-devel/2019-01/msg07650.html
> 
> All patches in the series have reviews now. Thanks everyone!
> 
> I've tested all patches with `make check-qtest -j' for all targets.
> The series is checkpatch-clean (just some warnings about __COVERITY__).
> 
> You can fetch the series from:
>   https://github.com/cota/qemu/tree/cpu-lock-v7

Having fixed the OSX build errors, Peter reported to me a hang on the x86_64
bios-tables-test with an arm32 host.  I have been able to replicate this.


(gdb) info thr
  Id   Target Id                                       Frame
  1    Thread 0xb35a72e0 (LWP 10966) "qemu-system-x86" 0xb606d138 in
pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0
  2    Thread 0xb35a3d30 (LWP 10967) "qemu-system-x86" 0xb5fe70fc in syscall ()
   from /usr/lib/libc.so.6
  3    Thread 0xa07fed30 (LWP 10968) "qemu-system-x86" 0xb5fe0688 in poll ()
   from /usr/lib/libc.so.6
* 4    Thread 0x9fdfed30 (LWP 10969) "qemu-system-x86" 0xb606d138 in
pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0

(gdb) thr 1
[Switching to thread 1 (Thread 0xb35a72e0 (LWP 10966))]
#0  0xb606d138 in pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0
(gdb) where
#0  0xb606d138 in pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0
#1  0x009a66a4 in qemu_cond_wait_impl (address@hidden,
    mutex=0xcad4c8 <qemu_global_mutex>,
    address@hidden "/home/rth/qemu/qemu/cpus-common.c",
    address@hidden) at /home/rth/qemu/qemu/util/qemu-thread-posix.c:161
#2  0x00692378 in run_on_cpu (address@hidden, func=<optimized out>,
    data=...) at /home/rth/qemu/qemu/cpus-common.c:166
#3  0x00604c18 in vapic_enable_tpr_reporting (enable=<optimized out>)
    at /home/rth/qemu/qemu/hw/i386/kvmvapic.c:507
#4  0x00710160 in qdev_reset_one (dev=<optimized out>, opaque=<optimized out>)
    at /home/rth/qemu/qemu/hw/core/qdev.c:250

(gdb) thr 4
[Switching to thread 4 (Thread 0x9fdfed30 (LWP 10969))]
#0  0xb606d138 in pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0
(gdb) where
#0  0xb606d138 in pthread_cond_wait@@GLIBC_2.4 () from /usr/lib/libpthread.so.0
#1  0x009a66a4 in qemu_cond_wait_impl (cond=0x1692ed8,
    mutex=0xcad4c8 <qemu_global_mutex>,
    address@hidden "/home/rth/qemu/qemu/cpus.c",
    address@hidden) at /home/rth/qemu/qemu/util/qemu-thread-posix.c:161
#2  0x00553070 in qemu_tcg_rr_cpu_thread_fn (arg=<optimized out>)
    at /home/rth/qemu/qemu/cpus.c:1647
#3  0x009a5f20 in qemu_thread_start (args=<optimized out>)
    at /home/rth/qemu/qemu/util/qemu-thread-posix.c:502


I had hoped that I would have been able to reproduce this on another host by
forcing rr mode.  But so far no luck.

Thoughts?


r~