18 Feb
2006
18 Feb
'06
6:03 p.m.
On Sat, 2006-02-18 at 13:55 -0800, Brad Fuller wrote:
Lee Revell wrote:
Presumably, a little bit of disk performance. Low latency always
involves giving up some performance, because it's a matter of doing some
kind of work in smaller chunks. I have not measured it.
This helps a lot:
echo 64 > /sys/block/hdc/queue/max_sectors_kb
(replace hdc with your drive, repeat for all of them)
Try that before you resort to patching the kernel.
IIRC PD is not the best designed RT app (GUI stuff can delay the RT
threads), but this might have improved lately.
What is given up by setting this to 64? I have a sata set at 1024 and an
IDE at 128. Certainly they were set at these settings for a reason (I
hope a good reason)
Heh, that's a funny story - it's actually the farthest thing from a good
reason I can imagine. The maximum IO size is determined by whether
48-bit addressing is in use which is determined by - wait for it - the
size of the drive! The sata drive is bigger than the IDE right?
Lee