I made a little research with the IO scheduler used on the linaro image because I am facing lot of iowaits and found the default one "cfq" is nearly 50% slower than "deadline".... When using "cfq" on my class 10 card, I get 6,7 mb/s compaired to deadline's 11.1mb/s Code: root@imx6-qsdl:~# echo "deadline" > /sys/block/mmcblk0/queue/scheduler root@imx6-qsdl:~# dd if=/dev/zero of=test bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 12.108 s, 11.1 MB/s root@imx6-qsdl:~# echo "noop" > /sys/block/mmcblk0/queue/scheduler root@imx6-qsdl:~# sync root@imx6-qsdl:~# dd if=/dev/zero of=test bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 20.311 s, 6.6 MB/s root@imx6-qsdl:~# echo "cfq" > /sys/block/mmcblk0/queue/scheduler root@imx6-qsdl:~# sync root@imx6-qsdl:~# dd if=/dev/zero of=test bs=1M count=128 128+0 records in 128+0 records out 134217728 bytes (134 MB) copied, 20.062 s, 6.7 MB/s
Interesting. I've not looked at 'Completely Fair Queuing' or 'Deadline' (or NOOP) until this post. I wonder if there are any IO Tuning experts around to look into this in detail.
I agree - after 2 days with my udoo I thing there are needed tunning experts for every aspect of the distribution Seems to be to unfinished and not fully optimized....
To be fair to them, they have said this themselves and have indicated they will now turn their attention to such matters. It would be good to see (read only) their ticket system/list of issues and the priorities thereof. I wonder to what extent they will allow community contributions to sorting out some of these issues.
yea your right, they have been very clear about how unpolished the distros are... which is good But i do admit a bit of frustration with not having an open bugzilla or something for tracking the known issues and the progress/priority. This is an open source, community project.. a bit a visibility would help the community focus more on things the Official UDOO team needs. They cant hen take the community input and commit it or whatever. I dont know, just seems to make a hell of a lot more sense, but im sure they will get to it, they are busy
Sure - I have no problems with that - the unoptimization itself is quite educative and fun more than ready to go raspbian for example. But on the other hand I'd like to have a second sdcard with a full working system ready out of box which I can use too.... :-D
