Hi ming

Thanks for your kindly response.

On 05/30/2018 04:22 PM, Ming Lei wrote:

quoted

quoted

you could keep the software queues as-is but add our own version of
flush_busy_ctxs() that only removes requests of the domain that we want.
If one domain gets backed up, that might get messy with long iterations,
though.

Yes, I also considered this approach :)
But the long iterations on every ctx->rq_list looks really inefficient.

Right, this list can be quite long if dispatch token is used up.

You might try to introduce per-domain list into ctx directly, then 'none'
may benefit from this change too since bio merge should be done
on the per-domain list actually.

Yes, it maybe good for merging of 'none', because the rq_list is split into 3
lists, and not need to iterate the whole rq_list any more.
But what's about the dispatch when there is no io scheduler.
We will dispatch request from ctx one by one at the moment.
If we have per-domain list in ctx, we have to introduce some policies to determine
which domain to dispatch, and these policies should be in io scheduler actually.

Thanks
Jianchao