Re: [Qemu-devel] [PATCH 0/4] curl: locking cleanups and fixes

[Paolo Bonzini <pbonzini@redhat.com>]

On 09/05/2017 18:03, Jeff Cody wrote:
> On Tue, May 09, 2017 at 11:15:06AM +0100, Richard W.M. Jones wrote:
>>
>> No I'm afraid this patch series does not fix the bug.
>>
>> The stack trace is below.
>>
>> Rich.
>>
> 
> I'm looking through qemu-defel, and I'm not finding a reference to the bug
> mentioned.  Maybe I'm just missing it... can you describe the bug or point
> me to the relevant email thread?

"Re: [Qemu-devel] [PULL 1/4] curl: do not use aio_context_acquire/release"

FWIW, Rich reported that patches 1-3 do work.  I'll look into the 
problems with patch 4 tomorrow.

Paolo

> 
> Thanks,
> Jeff
> 
>> Thread 4 (Thread 0x7f8595cf1700 (LWP 11235)):
>> #0  0x00007f86348e6700 in do_futex_wait () at /lib64/libpthread.so.0
>> #1  0x00007f86348e6813 in __new_sem_wait_slow () at /lib64/libpthread.so.0
>> #2  0x00005610e458519f in qemu_sem_timedwait (sem=sem@entry=0x5610e5db7508, ms=ms@entry=10000) at util/qemu-thread-posix.c:255
>> #3  0x00005610e458043c in worker_thread (opaque=0x5610e5db74a0)
>>     at util/thread-pool.c:92
>> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
>> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
>>
>> Thread 3 (Thread 0x7f8621347700 (LWP 10865)):
>> #0  0x00007f862e826837 in ioctl () at /lib64/libc.so.6
>> #1  0x00005610e4216387 in kvm_vcpu_ioctl (cpu=cpu@entry=0x5610e60f2030, type=type@entry=44672) at /home/rjones/d/qemu/kvm-all.c:2154
>> #2  0x00005610e42164be in kvm_cpu_exec (cpu=cpu@entry=0x5610e60f2030)
>>     at /home/rjones/d/qemu/kvm-all.c:1992
>> #3  0x00005610e4202f94 in qemu_kvm_cpu_thread_fn (arg=0x5610e60f2030)
>>     at /home/rjones/d/qemu/cpus.c:1118
>> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
>> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
>>
>> Thread 2 (Thread 0x7f8626559700 (LWP 10863)):
>> #0  0x00007f862e82b7a9 in syscall () at /lib64/libc.so.6
>> #1  0x00005610e4585325 in qemu_futex_wait (val=<optimized out>, f=<optimized out>) at /home/rjones/d/qemu/include/qemu/futex.h:26
>> #2  0x00005610e4585325 in qemu_event_wait (ev=ev@entry=0x5610e5019ee4 <rcu_call_ready_event>) at util/qemu-thread-posix.c:399
>> #3  0x00005610e459539e in call_rcu_thread (opaque=<optimized out>)
>>     at util/rcu.c:249
>> #4  0x00007f86348dd36d in start_thread () at /lib64/libpthread.so.0
>> #5  0x00007f862e830e0f in clone () at /lib64/libc.so.6
>>
>> Thread 1 (Thread 0x7f863757dc80 (LWP 10861)):
>> #0  0x00007f862e824dc6 in ppoll () at /lib64/libc.so.6
>> #1  0x00005610e4580ea9 in ppoll (__ss=0x0, __timeout=0x0, __nfds=<optimized out>, __fds=<optimized out>) at /usr/include/bits/poll2.h:77
>> #2  0x00005610e4580ea9 in qemu_poll_ns (fds=<optimized out>, nfds=<optimized out>, timeout=timeout@entry=-1) at util/qemu-timer.c:322
>> #3  0x00005610e4582af4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:622
>> #4  0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #5  0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e78afb70)
>>     at block/curl.c:871
>> #6  0x00005610e457fb1e in aio_bh_call (bh=0x5610e6128f10) at util/async.c:90
>> #7  0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #8  0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
>> #9  0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #10 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e6f01380)
>>     at block/curl.c:871
>> #11 0x00005610e457fb1e in aio_bh_call (bh=0x5610e6e1fff0) at util/async.c:90
>> #12 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #13 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
>> #14 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #15 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e77d6ec0)
>>     at block/curl.c:871
>> #16 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7229960) at util/async.c:90
>> #17 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #18 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
>> #19 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #20 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7877220)
>>     at block/curl.c:871
>> #21 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7054e20) at util/async.c:90
>> #22 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #23 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
>> #24 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #25 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7903cb0)
>>     at block/curl.c:871
>> #26 0x00005610e457fb1e in aio_bh_call (bh=0x5610e7903d10) at util/async.c:90
>> #27 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #28 0x00005610e4582cf4 in aio_poll (ctx=ctx@entry=0x5610e5d92860, blocking=<optimized out>) at util/aio-posix.c:682
>> #29 0x00007f8624848299 in curl_init_state (bs=<optimized out>, s=s@entry=0x5610e5defb10) at block/curl.c:490
>> #30 0x00007f8624848a51 in curl_readv_bh_cb (p=0x5610e7146fb0)
>>     at block/curl.c:871
>> #31 0x00005610e457fb1e in aio_bh_call (bh=0x5610e70593d0) at util/async.c:90
>> #32 0x00005610e457fb1e in aio_bh_poll (ctx=ctx@entry=0x5610e5d92860)
>>     at util/async.c:118
>> #33 0x00005610e45829c0 in aio_dispatch (ctx=0x5610e5d92860)
>>     at util/aio-posix.c:429
>> #34 0x00005610e457f9fe in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at util/async.c:261
>> #35 0x00007f863235d1d7 in g_main_context_dispatch () at /lib64/libglib-2.0.so.0
>> #36 0x00005610e4581c17 in glib_pollfds_poll () at util/main-loop.c:213
>> #37 0x00005610e4581c17 in os_host_main_loop_wait (timeout=<optimized out>)
>>     at util/main-loop.c:261
>> #38 0x00005610e4581c17 in main_loop_wait (nonblocking=<optimized out>)
>>     at util/main-loop.c:517
>> #39 0x00005610e41c3ad1 in main_loop () at vl.c:1899
>> #40 0x00005610e41c3ad1 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4719
>>
>>
>> -- 
>> Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
>> Read my programming and virtualization blog: http://rwmj.wordpress.com
>> virt-p2v converts physical machines to virtual machines.  Boot with a
>> live CD or over the network (PXE) and turn machines into KVM guests.
>> http://libguestfs.org/virt-v2v