how to speed up mock?

[Ville Skyttä]

(Not sure why this is cross-posted to devel, dropping it.)

On 04/03/2011 01:31 PM, Farkas Levente wrote:

> disk space is cheep.

Traditional rotational disk space is.

> can we speed up mock to
> somehow totally disable compressing root_cache?

Whether it speeds it up depends on how much CPU and disk I/O resources
the box has, but you can disable compression of the root cache by
setting compress_program to an empty string in mock's config.

On the box I have in front of me (single core Athlon64 3200+, pretty
fast SSD) the step where mock unpacks the F-14 root cache takes slightly
less than 5 seconds if it's lzop compressed, and slightly more than 3 if
it's not compressed.  pigz would be about 6 seconds and has somewhat
better compression than lzop but it's so much slower than lzop whenever
the root cache needs to be rebuilt (compressing it takes ~40 seconds
with pigz and gzip, ~7 with lzop) that it annoys me.  Anyway, compared
to common setups, I suspect the disk I/O vs CPU ratio of this box is
biased towards the former, and on this box I'll gladly take the root
cache size savings and pay the price of ~2 seconds per build for it.

I suggest you benchmark and find out what works best for you.  An easy
way to get approximate numbers is by looking into mock's state.log.