alohas dearest technical board members, I would like to kindly request the TBs input on a possible IO scheduler changing SRU for Kubuntu 14.04.
The gist of it is: all of ubuntu is using deadline scheduler, KDE's file indexer needs to set ioniceness to not hijack the computer on systems with HDDs, so Kubuntu needs to set the CFQ scheduler (which supports ioniceness) in such scenarios. We'd like to SRU a fix for this in 14.04 and are looking for input on the matter. CFQ is being set by the kubuntu-settings package in kubuntu installations starting with 14.10. [0] Unfortunately we and upstream did not notice that a lot of the speed problems WRT indexing in Kubuntu 14.04 came in fact from deadline being not very suitable for the way indexing is done (on HDDs, has to do with how deadline works also see [1] for a discussion on the matter). So we released with deadline (as per ubuntu default). Since then this has caused numerous bug reports, flame wars on various social media sites, complaints in forums general hostility towards upstream and the kubuntu team, and a lot of time wasted on rehashing why 14.04 is not delivering the quality that we and upstream intended. It is due to all of this that we are looking into landing an SRU [2] for 14.04 also forcing Kubuntu installations with HDDs to use the CFQ scheduler instead of deadline. SSD installations would not be affected and continue to use deadline. As seen in comment #5 of [2] it was suggested to wait until after the release of 14.10 and only then proceed with the SRU. Most Kubuntu devs do not appear to agree with this as being too conservative an approach. The possible fallout is highly limited in impact (could only make some things slower) and scope (only could do so on Kubuntu with HDD). I think Jonathan Riddell's comment sums it up pretty well: "we know upstream linux recommends it, we know baloo [kde indexer] recommends it, ubuntu kernel team don't seem too sure why they switched, we don't have any reason to think it'll cause problems" Would the technical board support a swifter resolution of the problem or indeed prefer waiting? TIA HS [0] http://goo.gl/9XFijy [1] http://irclogs.ubuntu.com/2014/10/08/%23ubuntu-kernel.html#t12:56 [2] https://bugs.launchpad.net/bugs/1378789 -- technical-board mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/technical-board
