Re: [Qemu-devel] [RFC 1/6] block: add request tracking

[Stefan Hajnoczi <stefanha@gmail.com>]

On Mon, Nov 7, 2011 at 11:00 AM, Zhi Yong Wu <zwu.kernel@gmail.com> wrote:
> On Mon, Oct 17, 2011 at 11:47 PM, Stefan Hajnoczi
> <stefanha@linux.vnet.ibm.com> wrote:
>> +/**
>> + * Enable tracking of incoming requests
>> + *
>> + * Request tracking can be safely used by multiple users at the same time,
>> + * there is an internal reference count to match start and stop calls.
>> + */
>> +void bdrv_start_request_tracking(BlockDriverState *bs)
>> +{
>> +    bs->request_tracking++;
>> +}
>> +
>> +/**
>> + * Disable tracking of incoming requests
>> + *
>> + * Note that in-flight requests are still tracked, this function only stops
>> + * tracking incoming requests.
>> + */
>> +void bdrv_stop_request_tracking(BlockDriverState *bs)
>> +{
>> +    bs->request_tracking--;
>> +}
> I don't understand what the real intention for the above functions is.
> IMHO, why can we not drop them?

I have dropped them after removing the g_malloc() as Kevin suggested.
The idea was to avoid the overhead of request tracking when no feature
is using request tracking.

Stefan