Thread: N900, ohmd, syspart, VM & swap tweaks
View Single Post
Tigerite is offline Tigerite
2011-06-01 , 11:04
Posts: 284 | Thanked: 320 times | Joined on May 2010 @ Peterborough, UK
#24
Ok, I've built the latest BFS from git tree, with both deadline and anticipatory enabled as modules within the config. Everything runs as smoothly as before, with no added overhead. To enable either one of them, you have to echo deadline or anticipatory to /sys/block/mmcblk0/queue/scheduler - this seems to automagically insert the corresponding module (probably best to rmmod if you then change back to noop or cfq at a later date, though, as they stay loaded). I did find a thread regarding anticipatory on Android and found this snippet to be quite interesting:

For instance anticipatory scheduler focuses on contiunous read and avoiding head movement which is not the case for flash drives.

Completely different rules apply here.

The community (Linux SSD) recommends NOOP or DEADLINE schedulers, I prefered DEADLINE for it's focus on preventing read starvation.
It works the best (elevator = deadline) for my Asus EEE PC 901 with SSD drives and attached SD cards.
Writes are slower, but there's much less lag when browsing web or opening folders because "read" operations have priority.
The same seems to work on my Galaxy S with stock JM1 with or without one-click-lag-fix.
..which makes me think deadline might be the best scheduler to use, even though the N900's drive isn't exactly an SSD?
Last edited by Tigerite; 2011-06-01 at 11:06.
 

The Following 3 Users Say Thank You to Tigerite For This Useful Post: