memory_compare script was changed to a 25% variance allowed

I first noticed this today while testing this version from the "testing" ppa

plainbox-provider-checkbox 0.9~c1~ppa~ubuntu14.04.1

Or I guess to put this into server scale, if I am cert testing a system with 1TiB of RAM, I could potentially not notice in my test results that up to 250Gib of RAM was missing, and no GPU in the world would account for that large of a discrepancy.

This was done in revision 2256:

checkbox-old:scripts:memory_compare: set an adaptive diff. threshold

To avoid false positive with systems sharing system memory with graphic
cards,

The variable threshold is set as follow:
- if total memory amount is 2 GB or less, then the threshold is 25%
- for more than 2 GB it's 20%
- and for more than 6 GB it goes back down to 10%.

And the code reflects this. Line 65:

    threshold = get_threshold(installed_memory)

and the get_threshold method:

def get_threshold(installed_memory):
    GB = 1024**3
    if installed_memory <= 2 * GB:
        return 25
    elif installed_memory <= 6 * GB:
        return 20
    else:
        return 10

This was done because a GPU can conceivably take, say, 256MB of memory, and on a 2-GB system that would put us over the 10% threshold (and yet be completely normal and explainable).

Now, if this is not working as expected, please let me know, but otherwise, maybe the only change we'd need to make is removing the unused and misleading THRESHOLD constant at the beginning.

yeah, that threw me. And your description makes sense, and yes, that does work, which does explain why I never noticed the change until now.

OK, let's mark this as "in progress" then. Thanks for reporting this, and for confirming it works as expected (hurray!).

By the way, the threshold is easily adjustable as you saw, so if you want it to be stricter in systems with more RAM (your rationale makes perfect sense), we can do that no problem.