Re: [StGit PATCH 0/2] push optimizations

2008/7/2 Karl Hasselström [off-list ref]:

Here's the git-apply call you asked for. You were right: it was a huge
speed-up.

I know, I've been through this couple of years ago :-)

I set up a benchmark to test it:

 * 32 directories, each containing 32 subdirectories, each containing
   32 small (and different) files.

Can you try with a Linux kernel like the -mm tree? You get normally
sized patches which might show a difference with the patch log. You
can clone the for-akpm branch on git://linux-arm.org/linux-2.6 and
just uncommit ~300 patches.

 * I set all this up with a python script feeding fast-import. A huge
   time-saver!

What is fast-import?

 * Pop patches, git-reset to upstream, then goto top patch. This
   makes sure that we use the new infrastructure to push, and that we
   get one file-level conflict in each patch.

Before the first patch, the "goto" command took 4:27 minutes,
wall-clock time. After the first patch, it took 1:31. After the
second, 0:48; one second or so slower than the stable branch (which
does not have a patch stack log).

One second is just noise and depends on how warm the caches are. You
could run a few times consecutively and discard the first result but
we don't need to be that accurate.

-- 
Catalin