Re: Question regarding heavy CPU during disk i/o
J Marler <jmarler-du@emarler.com> writes:
> I am running Debian Woody on a K7 850Mhz system with 384MB of RAM.
>
> My motherboard is an Abit KT7-RAID with VIA chipset and VIA IDE
> controllers. I have a Western Digital 60GB WDC600BB UDMA 100 hard
> drive, currently running only UDMA 66. I have the RAID controller
> disabled for simplicity sake (that may be a mistake as only the RAID
> controller will do UDMA 100).
>
> My question is this: Whenever I do any kind of "heavy" disk access,
> such as copying large files (10MB+), the CPU usage sky rockets and my
> system reacts slowly. Why? And how do I fix this?
>
> I have DMA access disabled with hdparm.
Well, this answers your first question. Without DMA, your CPU has to do
all the work. Fix it by enabling DMA.
> If I enable it, the system promptly locks hard. I have multicount
> enabled at 16. 32-bit i/o is enabled. readahead is enabled at 8.
> busstate is 1 (not sure what that is.)
>
> I am sure there is a simple answer to my question, but I have tinkered
> with this thing for too long now. I can't seem to figure it out.
>
> Any help would be greatly appreciated.
Only thing I can think of is to mess with your kernel config. Are you
running 2.4.x? Make sure you've enabled the via82cxxx driver, and read
the comments at the top of file
drivers/ide/via82cxxx.c
in your kernel source directory.
--
Brian Nelson <nelson@bignachos.com>
Reply to: