[Boost-build] Parallel vs serial gcc linker invocation

Subject: [Boost-build] Parallel vs serial gcc linker invocation
From: Jim Thoenen (jthoenen_at_[hidden])
Date: 2015-05-31 22:41:41

Hello,

My project uses b2 as our builder, and we have a large number of unit test
targets.  The quantity and structure of our targets is such that running
tests has become painfully slow due to the serialized linker invocation for
each tester, even though the testers are totally independent with respect
to each other.

As an experiment, in gcc.jam, I commented out the link rules'
"JAM_SEMAPHORE on $(targets)" lines to allow independent links to run in
parallel, and the speedup was dramatic.

It would be very nice if there was a feature or some mechanism to control
whether or not independent linker invocations are allowed to run in
parallel.  Thoughts?

Thank you,
Jim