On Thu, Oct 06, 2016 at 03:15:50PM +0200, Paolo Valente wrote: [..] > Shaohua, I have just realized that I have unconsciously defended a > wrong argument. Although all the facts that I have reported are > evidently true, I have argued as if the question was: "do we need to > throw away throttling because there is proportional, or do we need to > throw away proportional share because there is throttling?". This > question is simply wrong, as I think consciously (sorry for my > dissociated behavior :) ). I was wondering about the same. We need both and both should be able to work with fast devices of today using blk-mq interfaces without much overhead. > > The best goal to achieve is to have both a good throttling mechanism, > and a good proportional share scheduler. This goal would be valid if > even if there was just one important scenario for each of the two > approaches. The vulnus here is that you guys are constantly, and > rightly, working on solutions to achieve and consolidate reasonable > QoS guarantees, but an apparently very good proportional-share > scheduler has been kept off for years. If you (or others) have good > arguments to support this state of affairs, then this would probably > be an important point to discuss. Paolo, CFQ is legacy now and if we can come up with a proportional IO mechanism which works reasonably well with fast devices using blk-mq interfaces, that will be much more interesting. Vivek -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
