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Re: [Qemu-devel] [PATCH v1 1/3] block: block: introduce bdrv_io_plug() a
From: |
Ming Lei |
Subject: |
Re: [Qemu-devel] [PATCH v1 1/3] block: block: introduce bdrv_io_plug() and bdrv_io_unplug() |
Date: |
Tue, 1 Jul 2014 00:15:02 +0800 |
On Tue, Jul 1, 2014 at 12:10 AM, Paolo Bonzini <address@hidden> wrote:
> Il 30/06/2014 17:47, Ming Lei ha scritto:
>
>> From: Ming Lei <address@hidden>
>>
>> This patch introduces these two APIs so that following
>> patches can support queuing I/O requests and submitting them
>> at batch for improving I/O performance.
>>
>> Signed-off-by: Ming Lei <address@hidden>
>> ---
>> block.c | 22 ++++++++++++++++++++++
>> include/block/block.h | 3 +++
>> include/block/block_int.h | 4 ++++
>> 3 files changed, 29 insertions(+)
>>
>> diff --git a/block.c b/block.c
>> index 217f523..2b4ec5b 100644
>> --- a/block.c
>> +++ b/block.c
>> @@ -1910,6 +1910,7 @@ void bdrv_drain_all(void)
>> bool bs_busy;
>>
>> aio_context_acquire(aio_context);
>> + bdrv_io_unplug(bs);
>> bdrv_start_throttled_reqs(bs);
>> bs_busy = bdrv_requests_pending(bs);
>> bs_busy |= aio_poll(aio_context, bs_busy);
>> @@ -5774,3 +5775,24 @@ bool bdrv_is_first_non_filter(BlockDriverState
>> *candidate)
>>
>> return false;
>> }
>> +
>> +void bdrv_io_plug(BlockDriverState *bs)
>> +{
>> + BlockDriver *drv = bs->drv;
>> + if (drv && drv->bdrv_io_plug) {
>> + drv->bdrv_io_plug(bs);
>> + } else if (bs->file) {
>> + bdrv_io_plug(bs->file);
>> + }
>> +}
>> +
>> +int bdrv_io_unplug(BlockDriverState *bs)
>> +{
>> + BlockDriver *drv = bs->drv;
>> + if (drv && drv->bdrv_io_unplug) {
>> + return drv->bdrv_io_unplug(bs);
>> + } else if (bs->file) {
>> + return bdrv_io_unplug(bs->file);
>> + }
>> + return 0;
>
>
> I think this should return void (and that's how you use it in patch 3
> indeed). If you fix this you can add my Reviewed-by tag.
It can be used to trace how many IO are submitted at batch,
otherwise device can't know this information at all.
Thanks,
--
Ming Lei
[Qemu-devel] [PATCH v1 2/3] linux-aio: implement io plug and unplug, Ming Lei, 2014/06/30
[Qemu-devel] [PATCH v1 3/3] dataplane: submit I/O at batch, Ming Lei, 2014/06/30