Subject: Re: "git grep" parallelism question

From: John Keeping <[email-masked]>
Date: Mon, 29 Apr 2013 19:08:57 +0100

On Mon, Apr 29, 2013 at 08:04:10PM +0200, Thomas Rast wrote:
> John Keeping <[email-masked]> writes:
> 
> > On Mon, Apr 29, 2013 at 07:35:01PM +0530, Ramkumar Ramachandra wrote:
> >> On a related note, one place that IO parallelism can provide massive
> >> benefits is in executing shell scripts.  Accordingly, I always use the
> >> following commands to compile and test git respectively:
> >> 
> >>     make -j 8 CFLAGS="-g -O0 -Wall"
> >>     make -j 8 DEFAULT_TEST_TARGET=prove GIT_PROVE_OPTS="-j 16" test
> >> 
> >> i.e. always use 8 threads when the task is known to be CPU intensive,
> >> and always use 16 threads when the task is known to be IO intensive.
> >
> > On this tangent, I recently added a TEST_OUTPUT_DIRECTORY line to my
> > config.mak which points into a tmpfs mount.  Keeping all of the test
> > repositories in RAM makes the tests significantly faster for me and
> > works nicely when you have the patches in jk/test-output (without those
> > patches the individual tests work but the reporting of aggregate results
> > doesn't).
> 
> But that's been possible for quite some time now, using --root, or am I
> missing something?

No, I was the one missing something (--root to be precise).  But with
TEST_OUTPUT_DIRECTORY you also get the result files in your temporary
location, not just the trash directory.