On Mon, Jul 18, 2011 at 7:06 PM, Matthew Dillon <[email protected] > wrote:
> Ok, well this is interesting. Basically it comes down to whether we > want to starve read operations or whether we want to starve write > operations. > > The FreeBSD results starve read operations, while the DragonFly results > starve write operations. That's the entirety of the difference between > the two tests. > > Would using the disk scheduler's in FBSD/DFly help with this at all? FreeBSD includes a geom_sched class for enabling pluggable disk scheduler's (currently only round-robin algorithm is implemented). http://info.iet.unipi.it/~luigi/geom_sched/ And I believe DFly has dsched? > This is all with swapcache turned off. The only way to test in a > fair manner with swapcache turned on (with a SSD) is if the FreeBSD > test used a similar setup w/ZFS. > > ZFS includes it's own disk scheduler, so geom_sched wouldn't help in that case. Would be interesting to see a comparison of HAMMER+swapcache and ZFS+L2ARC, though. -- Freddie Cash [email protected]
