Git and buildworld running at the same time

Lately I've noticed that sometimes while running buildworld a top
window reports git running also. Up to now, I've surmised that 
this is intentional, with git providing some housekeeping function.

Yesterday a buildworld session was accompanied by a prolonged
interval of git running also, with a large memory footprint,
near 1GB. That seems rather excessive.

At the same time, it dawned on me that my recent habit has been
to run git pull, immediately followed by buildworld. Might it be
prudent to wait (how long?) to let git finish any housekeeping
triggered by the pull command? It seems likely that any overlap
could readily lead to inconsistencies which might account for
some of the buildworld problems I've been encountering lately.

Thanks for reading,

bob prohaska