Cache reported in top and my board crashing

[Bill]

I have been noticing that my board crashes when the amount reported as
"cache" in top reaches between 6000-7000K as I start applications.
So, I decided to write a test program that simply wrote a log message
using syslog to see if it was always crashed at the same amount. With
this program running, I notice the amount reported as cache starts at
about 3500K and increases gradually. When it reaches about 3700K, it
goes back to 3500K and repeats.

What causes the amount reported at cache in top to go back down? I am
hoping if I understand this that I may be able to modify my other
programs to keep the amount cached down and, thus, stop the crash.

I am running Linux 2.6.26 on powerpc.

[Bill]

As a test, I removed all of my software and ran a test program that
opened a file and repeatedly wrote "Hello World" to it (hwwrite). I
see similar behavior.

Watching top, the hwwrite program takes over 90% of the CPU. When
cache gets to 12000-16000, the CPU % for hwwrite goes down to 20-40%.
It then goes back up to over 90% and then crashes with the cache value
around 19000.

I would like to run a memory test, but the only one I have found is
for Intel processors. I am running a PowerPC on 2.6.26.

Any suggestions would be most appreciated.

[Unruh]

Post by Bill
As a test, I removed all of my software and ran a test program that
opened a file and repeatedly wrote "Hello World" to it (hwwrite). I
see similar behavior.

What king of file do you write to?

Post by Bill
Watching top, the hwwrite program takes over 90% of the CPU. When
cache gets to 12000-16000, the CPU % for hwwrite goes down to 20-40%.

Cache? Do you mean swap?

Post by Bill
It then goes back up to over 90% and then crashes with the cache value
around 19000.

Run out of disk space?

And what does "crash" mean? You computer falls onto the floor? Your car
screems through the garage door?

Post by Bill
I would like to run a memory test, but the only one I have found is
for Intel processors. I am running a PowerPC on 2.6.26.
Any suggestions would be most appreciated.

[Bill]

Problem solved. We thought we had 128 MB of RAM. Physically we did
but we were not able to use it because some registers were not set
correctly.