Re: [PATCH V7 1/4] blk-mq: refactor the code of issue request directly

From: jianchao.wang
Date: Wed Nov 14 2018 - 04:23:43 EST


Hi Ming

On 11/14/18 5:11 PM, Ming Lei wrote:
>>
>> - if (!blk_mq_get_dispatch_budget(hctx))
>> - goto insert;
>> + if (unlikely(!blk_mq_get_dispatch_budget(hctx)))
>> + goto out_unlock;
> The unlikely annotation is a bit misleading, since out-of-budget can
> happen frequently in case of low queue depth, and there are lots of
> such examples.
>

This could be good for the case for no .get_budget and getting budget success.
In case of out-of-budget, we insert the request which is slow path.
It should be OK. Maybe some comment should be added for this.

Thanks
Jianchao