OLPC upgrades

[John Watlington]

On Feb 4, 2009, at 12:47 AM, Bobby Powers wrote:

> On Tue, Feb 3, 2009 at 7:55 PM,  <david at lang.hm> wrote:
>> On Wed, 4 Feb 2009, Martin Langhoff wrote:
>>
>>> On Wed, Feb 4, 2009 at 1:03 PM,  <david at lang.hm> wrote:
>>>> Ok, what tools can I use to satisfy you of this 'opinion' that
>>>> applications start faster on either KDE or GNOME than on Sugar  
>>>> on the same
>>>> hardware.
>>>>
>>>> by the way, you are the first person I have heard dispute this.
>>>
>>> Erik has done a few things lately that made me change perspective.
>>> Most comparisons have been made against stuff running off the SD- 
>>> card,
>>> and made our Sugar/Fedora look very slow in comparison. Everyone
>>> jumped on Python/Sugar.
>>>
>>> However, our NAND is *slow*, it busy-waits, JFFS2 is slow, and Linux
>>> under a bit of mem pressure (and having no swap) starts discarding
>>> pages, assuming that disk reads are reasonably fast and
>>> non-cpu-blocking. But reading pages from the NAND turns out to be  
>>> slow
>>> and most importantly it pegs the CPU hard.
>>>
>>> Get the debxo or the vanilla fedoras running on the NAND. The
>>> performance delta is not what we thought it would be.
>>
>> I know that debxo will install on the NAND. I haven't done so on my
>> systems yet as I wanted to leave the NAND intact to test the official
>> builds. I'll go ahead and do this on one of my boxes.
>>
>> most of my testing has been via USB, do you have any idea how it  
>> compares
>> performance wise to the NAND and SD card?
SD >> USB > NAND

>> is there any ability to not use JFFS2 on the NAND?
>
> I believe UBIFS is the up and coming JFFS2 killer:
> http://www.linux-mtd.infradead.org/doc/ubifs_whitepaper.pdf
> I don't know the status of it tho, I believe there was some testing at
> 1CC recently with mixed results.

Testing of UBIFS at 1CC ran into a bug which was patched and
has now been running for months without problems.

See: http://wiki.laptop.org/go/UBIFS_on_XO

Cheers,
wad