Re: "git grep" parallelism question

From: John Keeping <john@keeping.me.uk>
Date: Apr 29, 2013, 16:18 UTC
Message-ID: <20130429161814.GJ472@serenity.lan>
In-Reply-To: <CALkWK0k6Gi_J6nDbrGPxDMmWC73CHXdj7a5ugC15YVrrycP=hA@mail.gmail.com>

On Mon, Apr 29, 2013 at 07:35:01PM +0530, Ramkumar Ramachandra wrote:

Show 9 quoted lines

> 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).