Messages in this thread | | | Date | Mon, 9 Jan 2017 14:46:00 -0500 | From | Tejun Heo <> | Subject | Re: [PATCH V5 05/17] blk-throttle: add upgrade logic for LIMIT_LOW state |
| |
Hello, again.
On Mon, Jan 09, 2017 at 01:40:53PM -0500, Tejun Heo wrote: > I think it'd be great to explain the above. It was a bit difficult > for me to follow. It's also interesting because we're tying state > transitions for both read and write together. blk-throtl has been > handling reads and writes independently, now the mode switching from > low to max is shared across reads and writes. I suppose it could be > fine but would it be complex to separate them out? It's weird to make > this one state shared across reads and writes while not for others or > was this sharing intentional?
I thought more about it and as the low limit is regulated by latency, it makes sense to make the state shared across reads and writes; otherwise, IOs in one direction could easily mess up the other direction. Can you please document that this is an intentional design and explain the rationale tho?
Thanks.
-- tejun
| |