On Tue, Jan 17, 2017 at 6:38 PM, Matthew Miller
On Tue, Jan 17, 2017 at 12:31:04PM -0500, Josh Boyer wrote:
> Yes, but doing that across all of Fedora is pointless. What works for
> the majority of Server users won't necessarily work for Cloud or
> Workstation. Also, the end user's ability to even discover that it's
> tunable varies greatly from one Edition to the next. One could expect
> sysadmins knowing about this and changing the default on their Server
> install. The Workstation end user may not be as low-level detail
> aware and could just suffer with poor performance because they think
> that's the only option.
Well, I'm starting from Michael's premise that deadline would be better
for latency for most desktop users (regardless of disk type), and
clearly better when using SSD. This leads me to a different conclusion
than the above.
It's irrelevant for cloud and any other virt deployment of Atomic or
Server. As far as I know, the special case on hardware where cfq is
better is the one I outlined (on hardware, single spindle, prefer
throughput, mixed workload) and I agree that it's okay to expect
sysadmins to handle that.
Well there are a few things to consider here ...
1) Afaik deadline does not support I/O priorities (ionice), whole CFQ
does. Which might be harmful when you have processes like tracker
competing for I/O in the background
2) What about external media? It might perform a bit better on
internal disks but what about USB connected storage?
3) Given the recent developments upstream (BFQ and multi queue)
shouldn't we rather wait for that?