On Mon, Jun 1, 2015 at 1:08 PM, Miroslav Suchý <msuchy(a)redhat.com> wrote:
Dne 31.5.2015 v 21:50 Mike McLean napsal(a):
> Also, some builders do not necessarily have a lot of ram. Some buildroots are large,
some sources are extremely large
> (e.g. texlive). If we do this, it will need to be configurable, probably per-package
or per-tag.
The devils in detail is that you do *not* need to have a lot of ram. Just a lot of swap
disk.
And a lot of swap disk can cause the IO issues that you mention and
ultimately lead to performance problems.
E.g. in Copr we had reserved 50 GB for mock chroot. And now instead
of that, we now have 50 GB swap.
Therefore you never ever can have oversized tmpfs, because size of tmpfs is 50 GB, but
space for that is 5GB RAM + 50 GB
swap.
Yes, but it still filters down to IOPs on the disk one way or the other.
So you consume the same resource. And you get big performance
increase.
What package set did you test this against?