For example, one disk of one guest is hot plugout, its other disks
should not be affected if those disks also enable I/O throttling. But
if one whole VM need to be stored, all throttled requests for all
disks need to be drained.
On Mon, Feb 20, 2012 at 5:26 PM, Kevin Wolf <kw...@redhat.com> wrote:
> Am 20.02.2012 05:50, schrieb zwu.ker...@gmail.com:
>> From: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
>>
>> If one guest has multiple disks with enabling I/O throttling function
>> separately, when draining activities are done, some requests maybe are in
>> the throttled queue; So we need to restart them at first.
>>
>> Moreover, when only one disk need to be drained such as hotplug out, if
>> another disk still has some requests in its throttled queue, these request
>> should not be effected.
>>
>> Signed-off-by: Zhi Yong Wu <wu...@linux.vnet.ibm.com>
>> ---
>> block.c | 29 ++++++++++++++++++++++-------
>> block_int.h | 1 +
>> 2 files changed, 23 insertions(+), 7 deletions(-)
>>
>> diff --git a/block.c b/block.c
>> index ae297bb..f78df78 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -853,25 +853,40 @@ void bdrv_close_all(void)
>> }
>> }
>>
>> -/*
>> - * Wait for pending requests to complete across all BlockDriverStates
>> - *
>> - * This function does not flush data to disk, use bdrv_flush_all() for that
>> - * after calling this function.
>> - */
>> -void bdrv_drain_all(void)
>> +void bdrv_drain_request(BlockDriverState *throttled_bs)
>> {
>> BlockDriverState *bs;
>>
>> + QTAILQ_FOREACH(bs, &bdrv_states, list) {
>> + if (throttled_bs && throttled_bs != bs) {
>> + continue;
>> + }
>> + qemu_co_queue_restart_all(&bs->throttled_reqs);
>> + }
>> +
>> qemu_aio_flush();
>
> Why doesn't qemu_aio_flush() invoke whatever is needed? I think this is
> the real bug that should be fixed.
>
> Kevin
--
Regards,
Zhi Yong Wu
