----- Original Message -----
From: "Michael Robinton" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Sunday, March 19, 2000 9:54 AM
Subject: raid parity and mmx processor
> As I understand it, the kernel tests parity calc speed and decides to
> use/not use mmx based on which is faster.
>
> Assuming an otherwise heavily loaded cpu, would it not be better to use
> mmx even though slightly slower just to free up cpu cycles for other
tasks.
If you are doing the calculations faster, it takes shorter time before the
CPU is free to do other things. Fastest is fastest.
>
> If I don't have the right picture here, someone please provide an
> explaination of where the cpu cycles go to raid.
>
> This reason for my question is the amount of "nice" cycles on one of my
> machines that is fairly busy. Only raid5d is niced, and I'm running a
> load factor over one consistently with only about a 20% cpu load. It
> appears most of the cpu cycles in use go to raid5 -- presumably parity
> calculations.
What kinda disks are you running on? SCSI? IDE? If IDE, do you have all nice
things such as DMA transfers enabled?
>
> Assuming I'm not too far off base, it would be nice to have a /proc
> option or at least a compile option to force use of mmx for raid parity
> and a way to run the parity calculation test manually to see the
difference
> between the two methods.
Maybe not for speed, but for bug tracing. Anyway, that would be good.
>
> Michael
_____________________________________________________
| Martin Eriksson <[EMAIL PROTECTED]>
| http://www.fysnet.nu/
| ICQ: 5869159
