Re: Drastic jump in the time required for the test suite

From: Dennis Kaarsemaker <dennis@kaarsemaker.net>
Date: Oct 20, 2016, 20:40 UTC
Message-ID: <1476996017.28685.10.camel@kaarsemaker.net>
In-Reply-To: <20161020123111.qnbsainul2g54z4z@sigill.intra.peff.net>

On Thu, 2016-10-20 at 08:31 -0400, Jeff King wrote:

Show 5 quoted lines

> I'm also not entirely convinced that the test suite being a shell script
> is the main culprit for its slowness. We run git a lot of times, and
> that's inherent in testing it. I ran the whole test suite under
> "strace -f -e execve". There are ~335K execs. Here's the breakdown of
> the top ones:

You're measuring execve's, but fork (well, fork emulation. There's no actual fork) is also expensive on windows iirc, so subshells add a lot to this cost. That said, strace -eclone says that a 'make test' forks ~408k times, and while this is significantly more than the amount of execs in your example, this does include cvs and svn tests and it's still in the same ballpark.

D.