On Fri, Jul 26, 2019 at 07:05:50PM +0200, Santiago Vila wrote:
>...
> https://people.debian.org/~sanvila/single-cpu/
>...
> The practical implications of this is that we are currently forcing
> users to spend extra money if they want *assurance* that all the
> packages (and not just "most" of them) will build, which is a pity.
Your "assurance that all the packages will build" only applies to the
single-cpu part of your setup.
This Intel Atom instance you were using this year seems to have only
1 GB RAM and 25 GB storage, and you mention that you had to exclude
all packages that need more than 1 GB RAM.
Excluding these usually larger packages also makes your data unreliable.
Small packages with short build time don't benefit that much from
parallel building, but for huge packages with thousands of source files
like gcc or libreoffice where build time matters most the build time
tends to correlate quite well with the number of CPUs. And these huge
packages are where a large part of build time is spent when rebuilding
the archive.
Your "forcing users to spend extra money" claim might not be true when
giving the actual assurance that all packages should build - it omits
the costs of having to actually pay for provisioning sufficient RAM and
storage for a longer amount of time when building on single-core.
How much would you be paying per month for a single-core VM
with 8 GB RAM and 80 GB storage?
If you give your current single-cpu VM 2 GB of RAM plus the same amount
of swap this would be an economical setup that can build > 99% of all
packages on amd64.
A VM that gives the *assurance* that all the packages will build has
to be a lot larger, and will be oversized for most packages.
The economical setup will never be able to build all packages,
and the safe way to create the assurance setup will always be
to use the same specs as the buildd VMs.
cu
Adrian
--
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed
