Re: SCSI Kernel Problem - BAD

Simon Shapiro (Shimon@i-connect.net)
Tue, 12 Mar 1996 14:12:34 -0600 (CST)


Hi Alan Cox; On 12-Mar-96 you wrote:
> > > problem is more severe when the I/O rate is high. not the amount of data
> > as much as the number of I/O operations per second. In a PC, these are
> > typically directly related to interrupts. I also noticed that a busy NFS
> > connection will aggravate it even more. and I just saw that when NFS was
> > busy on these partitions, I was loosing interrupts on the wd.c driver.
>
> Heavy NFS load significantly increases the probability of GFP_ATOMIC or
> GFP_DMA memory allocations failing. There are also other things that will
> start to happen at this load (clustering attempts fail, the request queue is
> full, buffer cache grow/shrink). Is it worth trying these one at a time -
> eg a 4 item request queue and seeing if you can break it.
>
> Alan
>
Thanx ( and Hi! ) Alan. I can reproduce the problem easily without any nfs
activity. As I said elsewhere, it does not smell of queue (or other resource)
overflow. I can load the machine to load average of 4-6 and it will be fine.
Do something it hates, on an idle machine - Poof!

Sincerely Yours,
(Sent on 03/12/96, 14:12:34)
Simon Shapiro i-Connect.Net, a Division of iConnect Corp.
Shimon@i-Connect.Net 13455 SW Allen Blvd., Suite 140 Beaverton OR 97008