Re: [Qemu-devel] [PATCH COLO-Frame v10 06/38] migration: Integrate COLO checkpoint process into loadvm

[zhanghailiang <zhang.zhanghailiang@huawei.com>]

On 2015/11/7 1:29, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
>> Switch from normal migration loadvm process into COLO checkpoint process if
>> COLO mode is enabled.
>> We add three new members to struct MigrationIncomingState, 'have_colo_incoming_thread'
>> and 'colo_incoming_thread' record the colo related threads for secondary VM,
>> 'migration_incoming_co' records the original migration incoming coroutine.
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
>> ---
>> v10: fix a bug about fd leak which is found by Dave.
>
> <snip>
>
>> diff --git a/migration/migration.c b/migration/migration.c
>> index cf83531..7d8cd38 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -288,6 +288,27 @@ static void process_incoming_migration_co(void *opaque)
>>                         MIGRATION_STATUS_ACTIVE);
>>       ret = qemu_loadvm_state(f);
>>
>> +    if (!ret) {
>> +        /* Make sure all file formats flush their mutable metadata */
>> +        bdrv_invalidate_cache_all(&local_err);
>> +        if (local_err) {
>> +            error_report_err(local_err);
>> +            migrate_decompress_threads_join();
>> +            exit(EXIT_FAILURE);
>> +        }
>> +    }
>
> Are you moving this code? Because I think the bdrv_invalidate_cache_all is a few lines
> below here - just....
>
>> +    /* we get colo info, and know if we are in colo mode */
>> +    if (!ret && migration_incoming_enable_colo()) {
>> +        mis->migration_incoming_co = qemu_coroutine_self();
>> +        qemu_thread_create(&mis->colo_incoming_thread, "colo incoming",
>> +             colo_process_incoming_thread, mis, QEMU_THREAD_JOINABLE);
>> +        mis->have_colo_incoming_thread = true;
>> +        qemu_coroutine_yield();
>> +
>> +        /* Wait checkpoint incoming thread exit before free resource */
>> +        qemu_thread_join(&mis->colo_incoming_thread);
>> +    }
>> +
>>       qemu_fclose(f);
>>       free_xbzrle_decoded_buf();
>>       migration_incoming_state_destroy();
>
>
> .... here in my current head world; so shouldn't you be deleting
> the bdrv_invalidate_cache_all here?
>

Good catch! I deleted it in patch 38, which should be moved into
this patch. I will fix it in next version.

Thanks,
zhanghailiang

> (Otherwise OK)
>
> Dave
>
>> diff --git a/stubs/migration-colo.c b/stubs/migration-colo.c
>> index acddca6..c12516e 100644
>> --- a/stubs/migration-colo.c
>> +++ b/stubs/migration-colo.c
>> @@ -22,6 +22,16 @@ bool migration_in_colo_state(void)
>>       return false;
>>   }
>>
>> +bool migration_incoming_in_colo_state(void)
>> +{
>> +    return false;
>> +}
>> +
>>   void migrate_start_colo_process(MigrationState *s)
>>   {
>>   }
>> +
>> +void *colo_process_incoming_thread(void *opaque)
>> +{
>> +    return NULL;
>> +}
>> --
>> 1.8.3.1
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
> .
>