I really enjoy when people dig into things like this and report their findings. Having said that, I question the wisdom of "bothering" with this sort of thing. Everything you do that's non-standard or works against a system's default behavior incurs a cost. It's yet another thing you have to replicate when you migrate to a new version, change provisioning systems, etc.<p>And for what benefit? A few hundred syscalls per second? Linux syscalls are fast enough that something of that magnitude shouldn't matter much. Given that /etc/localtime will certainly be in cache with that frequency of access, a stat() should do little work in the kernel to return, so that won't be slow either.<p>It's good that they did some benchmarking to look at the differences, but this feels like a premature optimization to me. I can't imagine that this did anything but make their application a tiny fraction of a percent faster. Was it worth the time to dig into that for this increase? Was it worth the maintenance cost I mention in my first paragraph? I wouldn't think so.<p>I'm really trying not to take a crap on what they did; as I said, it's really cool to dig into these sorts of abstractions and find out where they're inefficient or leak (or just great as a learning exercise; we all depend on a mountain of code that most people don't understand at all). But, when looked at from a holistic systems approach, a grab bag of little "tweaks" like this can become harmful in the long run.