[Bug bootstrap/84402] New: [meta] GCC build system: parallelism bottleneck

["marxin at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84402

            Bug ID: 84402
           Summary: [meta] GCC build system: parallelism bottleneck
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: bootstrap
          Assignee: unassigned at gcc dot gnu.org
          Reporter: marxin at gcc dot gnu.org
  Target Milestone: ---

As discussed yesterday on IRC, current build of GCC has various issues that
make it not fully parallelable on machines with higher number of CPUs.

I've did a hack to make where I recorded timestamp when a target is triggered
and finished:
https://github.com/marxin/make/tree/timestamp

Then I built GCC with -j1 and used following parser to generate reports:
https://github.com/marxin/script-misc/blob/master/parse-make-log.py

I prepared various reports that I'm going to add as attachments.