Jon Nelson wrote:
On Wed, 4 Apr 2007, Bill Anderson wrote:
I noticed that the default elevator applies to everything, including USB memory sticks. I thought the block device driver would change the I/O scheduler to something more appropriate for a memory stick, such as the noop scheduler. I switched to the noop scheduler for just the memory stick, and there was an improvement in performance. I haven't done a detailed statistical analysis to verify my empirical impression.
I have a few questions: 1) Is there a reason for the block device driver not changing the I/O scheduler to noop? 2) How do I modify HAL to change the I/O scheduler when it detects that a hotplug for a memory stick?
I can't answer (1), and (2) is probably pretty easy. However, let me offer an alternative:
set the *default* I/O scheduler (there /are/ several schedulers, you know) to noop and then at boot time re-set your HDD (or whatever local devices you want to change back) to "anticipatory" (or whatever you use).
-- Carpe diem - Seize the day. Carp in denim - There's a fish in my pants!
Jon Nelson
Setting elevator=<somevalue> as boot command changes the default scheduler. It would really slow down the disk until it reached the boot.local script. Under Suse 10.2 and FC6, the kernel default scheduler is CFQ. I still want CFQ for the USB DVD drive, or a thumb drive. Thus, I am looking for a way for to configure HAL to change the elevator from cfq to noop upon detection of the memory stick. Bill Anderson -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org For additional commands, e-mail: opensuse+help@opensuse.org