Apparent performance regression 8.3@ -> 8.4 at r255966?

[David Wolfskill]

On Thu, Oct 10, 2013 at 04:02:47PM +0200, Ivan Voras wrote:
> On 07/10/2013 19:28, David Wolfskill wrote:> At work, we have a bunch of
> machines that developers use to build some
> > software.  The machines presently run FreeBSD/amd64 8.3-STABLE @rxxxxxx
> > (with a few local patches, which have since been committed to stable/8),
> > and the software is built within a 32-bit jail.
> ....
> So, the test machine is exactly the same as the old machines? Does the
> hardware upgrade coincide with 8.4-STABLE upgrade?

The only hardware upgrade was to increase RAM from 6GB to 96GB,
which was done for all of the machines being discussed.  The machine
I'm using for testing configurations now is the one I used to
test configurations before we bought the machines we've now deployed.

I cite 8.4 as a (vague) reference point; more specifically, I used a
snapshot of stable/8.  More precisely, it's stab le/8 @r255978.

> At a guess, you also might be hitting a problem with either NUMA (which
> would mean the difference you encountered is pretty much random,
> depending on how the memory from your processes was allocated), or a
> generic scheduler issue (IIRC, FreeBSD 9 series was found to be much
> more scalable for > 16 CPUs).

I'm hoping to demonstrate that -- but first, I need to get demonstrate
something that fixes some known bugs while not saddling the developers
with a 12% increase in build times.  And I've been trying (when my
test machine has been available to me) to get this done for nearly
a year, now.  (There is also a perception that "jumping" from 8.x
to 9.x is "scary".  I am reminded of the "It's just a leaf!" sequence
near the beginning of "A Bug's Life.")

> Just a thought - you *could* set up an 8-STABLE jail in a 9-STABLE
> environment if you need the 8-STABLE libraries for your software.

The "32-bit jail" is actually a 7.1-R [+ a few patches] environment as
it is.

Thanks for responding. :-}

Peace,
david
-- 
David H. Wolfskill				david at catwhisker.org
Taliban: Evil cowards with guns afraid of truth from a 14-year old girl.

See http://www.catwhisker.org/~david/publickey.gpg for my public key.
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