Re: "git grep" parallelism question

Linus Torvalds [off-list ref] writes:

Anyway, I think your patch is good if for no other reason that it
allows this kind of testing, but at least for my machine, clearly the
current default of eight threads is actually "good enough". Maybe
somebody with a very different machine might want to run the above
script and see if how sensitive other machines are to this parameter..

I think the last time Duy, Peff, me and others looked into grep
threading (which was a while ago) we basically reached the conclusion
that it's very unstable across machines.

Back then I tested things on a 2x6-core Xeon OS X machine and there the
performance (for the hot-cache, worktree case, which should parallelize
nicely) flatlines at 5 threads for no apparent reason.

-- 
Thomas Rast
trast@{inf,student}.ethz.ch