Our gitweb instance is used daily by me and probably a few other people here, so it would be very, very nice to improve its performance. From irc...
15:00 < atagar> Is the host providing our gitweb instance resource starved? I use it daily and the initial page load often happens at a crawl, making me twitch. Feels like it's populating a cache since it's fine after that. 15:22 < atagar> Tried wating for fourty minutes then reloading - 15s for the first load and 6s for all following. Gitweb is a cgi that gets executed on each run (I don't recall any caching in it) so it would be nice to know what's leading to the almost 3x improvement. There's few page resources so it shouldn't be client side caching. 15:23 < rransom__> The OS did it. 15:31 < atagar> it would be nice if the os kept doing it :) 02:55 < Sebastian> atagar: gitweb reads a bunch of things from disk. When the OS filesystem caches are cold, that takes a long time. Since it's on a VM with constrained i/o and memory, stuff takes extra long sometimes. 02:55 < Sebastian> atagar: there are gitweb versions with caching. We'll eventually upgrade, probably
On first glance there was a GSoC project from '08 for gitweb caching, and drupal had a ticket where they did this. The only other note I found was...
"If your repository set is large and you are expecting a lot of users, you may want to look at the caching forks used by high-traffic sites like kernel.org or repo.or.cz." 
Pity since I was hoping to find nice instructions. Oh well. Let me know if I can help with making this happen.