"Daniel P. Berrange" <berra...@redhat.com> wrote:
> On Tue, Aug 08, 2017 at 06:26:25PM +0200, Juan Quintela wrote:
>> We make the locking and the transfer of information specific, even if we
>> are still receiving things through the main thread.
>>
>> Signed-off-by: Juan Quintela <quint...@redhat.com>
>>
>> --
>>
>> We split when we create the main channel and where we start the main
>> migration thread, so we wait for the creation of the other threads.
>>
>> Use multifd_clear_group().
>> ---
>> migration/migration.c | 7 ++++---
>> migration/migration.h | 1 +
>> migration/ram.c | 55
>> +++++++++++++++++++++++++++++++++++++++++++++++----
>> migration/socket.c | 2 +-
>> 4 files changed, 57 insertions(+), 8 deletions(-)
>
>
>> diff --git a/migration/socket.c b/migration/socket.c
>> index 5dd6f42..3af9f7c 100644
>> --- a/migration/socket.c
>> +++ b/migration/socket.c
>> @@ -183,12 +183,12 @@ static gboolean
>> socket_accept_incoming_migration(QIOChannel *ioc,
>>
>> qio_channel_set_name(QIO_CHANNEL(sioc), "migration-socket-incoming");
>> migration_channel_process_incoming(QIO_CHANNEL(sioc));
>> - object_unref(OBJECT(sioc));
>
> AFAICT, migration_channel_process_incoming() acquires its own reference
> on 'sioc', so removing this object_unref means the code is now leaking a
> reference
Nack.
I did it and ended with a segmentation fault because reference count was
bad.
(qemu)
Thread 6 "multifdrecv_0" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7fff9f9ff700 (LWP 10065)]
0x00005555559c12f8 in type_is_ancestor (type=0xb60f18247c894860,
target_type=0x555556531b30) at /mnt/kvm/qemu/cleanup/qom/object.c:217
217 while (type) {
(gdb) bt
#0 0x00005555559c12f8 in type_is_ancestor (type=0xb60f18247c894860,
target_type=0x555556531b30) at /mnt/kvm/qemu/cleanup/qom/object.c:217
#1 0x00005555559c1dbb in object_class_dynamic_cast
(class=class@entry=0x7ffff2cb3ce8 <main_arena+520>,
typename=typename@entry=0x555555aa6d91 "qio-channel")
at /mnt/kvm/qemu/cleanup/qom/object.c:691
#2 0x00005555559c1ed2 in object_class_dynamic_cast_assert
(class=0x7ffff2cb3ce8 <main_arena+520>, typename=typename@entry=0x555555aa6d91
"qio-channel", file=file@entry=0x555555b88208
"/mnt/kvm/qemu/cleanup/io/channel.c", line=line@entry=56,
func=func@entry=0x555555b884e0 <__func__.22671> "qio_channel_readv_full")
at /mnt/kvm/qemu/cleanup/qom/object.c:723
#3 0x0000555555a3d4d7 in qio_channel_readv_full (ioc=0x5555568c5a00,
iov=0x7fff900008c0, niov=15, fds=0x0, nfds=0x0, errp=0x7fff9f9fe950)
at /mnt/kvm/qemu/cleanup/io/channel.c:56
#4 0x0000555555a3ddc2 in qio_channel_readv (errp=0x7fff9f9fe950,
niov=<optimized out>, iov=<optimized out>, ioc=0x5555568c5a00)
at /mnt/kvm/qemu/cleanup/io/channel.c:197
#5 0x0000555555a3ddc2 in qio_channel_readv_all_eof (ioc=0x5555568c5a00,
iov=<optimized out>, niov=<optimized out>, errp=errp@entry=0x7fff9f9fe950)
at /mnt/kvm/qemu/cleanup/io/channel.c:106
#6 0x0000555555a3de79 in qio_channel_readv_all (ioc=<optimized out>,
iov=<optimized out>, niov=<optimized out>, errp=errp@entry=0x7fff9f9fe950)
at /mnt/kvm/qemu/cleanup/io/channel.c:142
#7 0x0000555555794768 in multifd_recv_thread (opaque=0x5555570e5e00)
---Type <return> to continue, or q <return> to quit---up
at /mnt/kvm/qemu/cleanup/migration/ram.c:722
#8 0x00007ffff2cc036d in start_thread (arg=0x7fff9f9ff700)
at pthread_create.c:456
#9 0x00007ffff29f8bbf in clone ()
at ../sysdeps/unix/sysv/linux/x86_64/clone.S:97
(gdb) up
Removing this unref fixed things, so I think that the accounting is good
(famous last words).
Later, Juan.
