#1149937 ifcopenshell: Please consider reducing the value of --required-mem

Package:
src:ifcopenshell
Source:
src:ifcopenshell
Submitter:
Aurelien Jarno
Date:
2026-10-20 21:37:02 UTC
Severity:
normal
#1149937#5
Date:
2026-10-04 15:02:27 UTC
From:
To:
Hi,

Starting with ifcopenshell version 0.8.1+dfsg1-9, the package use
guess-concurrency to limit parallel workers, which is a good move.
However on all build daemons which currently have build it, it also has
significantly increased the build time. Therefore it seems that the
current value of 8G is not optimal:
- 8G seems quite high, have you actually measured it? From a quick look
  on the loong64 build, i never spotted it taking more than 3G
- Hardware or VMs usually use an integer value in G for the RAM (and
  often a power of 2). There is always a bit of RAM lost (kernel code or
  data, reserved memory, ...) and this is enough to get just below the
  8G per core. For example on a host with 32G of memory, this limits the
  number of jobs to 3.

Regards
Aurelien
#1149937#10
Date:
2026-10-20 21:34:09 UTC
From:
To:
Hi,

I did a full recording of the memory used by each compiler call during
the build on an amd64 host. There is indeed one call at 7.7G.

There are a bit more than 800 calls, with only 5 calls above 4G and 25
calls above 2G, with an average of 938M and a median of 885M.

The biggest calls by decreasing orders are 7.7G, 5.9G, 5.2G, 4.9G and
4G. Therefore I think it makes sense to at least reduce --required-mem
to "7.7G,5.9G", or if you do not like decimal numbers to "8G,6G"

Regards
Aurelien