Re: [PATCH 0/2] optimizing pack access on "read only" fetch repos

On Thu, Jan 31, 2013 at 08:47:37AM -0800, Shawn O. Pearce wrote:

quoted

quoted

 - System resource cost we incur by having to keep 50 file
   descriptors open and maintaining 50 mmap windows will reduce by
   50 fold.

I wonder how measurable that is (and if it matters on Linux versus less
efficient platforms).

It does matter. We know it has a negative impact on JGit even on Linux
for example. You don't want 300 packs in a repository. 50 might be
tolerable. 300 is not.

I'd love to see numbers if you have them. It's not that I don't believe
it is slower, but knowing _how much_ is important when thinking about
what kind of performance increase we are looking to get (which in turn
impacts how much effort to put into the repacking).

-Peff