Hi Tom, On Fri, 2013-04-12 at 18:41 +0000, Counihan, Tom wrote: > Hi Artem, et al, > > If I'm correct IVI is using the CFQ scheduler - correct?
Yes. > I wonder would it be worth considering moving to NOOP or even > Deadline scheduler - I suspect we won't see spinning rust in IVI for > quite some time to come? Currently we have CFQ to be the default I/O scheduler, and NOOP is also available. I will also enable the Deadline scheduler today. So all 3 will be available. One can switch the I/O scheduler for any particular block device via sysfs. E.g., $ cat /sys/class/block/sda/queue/scheduler noop [cfq] shows that the current I/O scheduler for /dev/sda is CFQ. Writing 'noop' to this file would switch to the Noop I/O scheduler. Your request is about making Noop or Deadline to be the default. I am generally fine with it, but I'd like to make it more consciously. I'd probably put it this way: the I/O scheduler which allows for the fastest system boot should be made the default one in Tizen IVI. Do you agree? If not, what would be your criteria? My point is that there is no best I/O scheduler, the workload is the primary defining factor, and the HW (SSD vs HDD, etc) is the second defining factor. Anyway, if you agree with my criteria, then I'd say that the current Tizen IVI distro is not really ready for tuning the boot time yet, so I do not think we can make the right decision right now, and therefor I'd leave the CFQ to be the default so far. And as I said, one can switch the scheduler for a specific device using the sysfs switch, or even make a udev rule which will assign the I/O scheduler for a specific device. -- Best Regards, Artem Bityutskiy _______________________________________________ IVI mailing list [email protected] https://lists.tizen.org/listinfo/ivi
