[maemo-developers] [maemo-developers] defective memory?

[From: Frantisek Dufka]

Siarhei Siamashka wrote:
> On 9/19/06, Frantisek Dufka wrote:
> 
>> Just few ideas:
>> software - bug is swapping/pagefault code?, bad ram timings?, too high
>> CPU clock?
> 
> That's an interesting idea, It seems to be worth trying to downclock
> the device and check if it improves stability. Does anybody know how
> to do this?

Anybody is me, you forgot cc to the list. I think there is some table 
with clocks in kernel source. Some board specific file related to n770. 
I think there is some constant like 250000000.

> request 40MB too early, it will fail. Did you run memtester with my
> last patch? It contains this gradually increasing allocation size
> trick automatically, so you don't need to run memtester many times and
> can specify 40MB at once.

Yes, it starts at 20 and goes slowly up. But still 25 were the limit. 
After reboot 40MB is really possible (no error again). I was not runing 
anything special before reboot so that 15MB difference is strange.

> 
> Surely it would be much better if memtester could access (almost) all
> the physical memory at once. Otherwise it can't provide reliable and
> trustworthy results. Probably boot time memtester similar to memtest86
> that runs before the system loads can do this work best, but I wonder
> if it is easy to access framebuffer to print some results from it.

Check /mnt/initfs/linuxrc source. There is text2screen binary or you can 
probably enable framebuffer console in kernel. Also when you install the 
BootMenu you can play with replacing /sbin/init or init scripts on mmc 
card and boot from it. In fact if you compile memtester as uclibc binary 
it can be included in initfs image and run without mounting rootfs. 
text2screen can display only parameters but it is not so hard to wrap it 
in 'for' loop in shell while reading file.

Frantisek