Re: Debugging git-commit slowness on a large repo

On Wed, Dec 7, 2011 at 8:48 AM, Joshua Redstone [off-list ref] wrote:

I tried doing a 'git read-tree HEAD' before each 'git add ; git commit'
iteration, and the time for git-commit jumped from about 1 second to about
8 seconds.  That is a pretty dramatic slowdown.  Any idea why?  I wonder
if that's related to the overall commit slowness.

How big is your working directory? "git ls-files | wc -l" should show
it. Try "git read-tree HEAD; git add; git write-tree" and see if the
write-tree part takes as much time as commit. write-tree is mainly
about cache-tree generation.

@Carlos and/or @Junio, can you point me at any docs/code to understand
what a tree-cache is and how it differs from the index?  I did a google
search for [git tree-cache index], but nothing popped out.

Have a look at Documentation/technical/index-format.txt. Cache tree
extension is near the end.
-- 
Duy