On Wed, 15 Sep 2004, Zeev Suraski wrote: > Can you share with us what kind of performance increase (vs. the 'much > inferior' realpath cache or even plain vanilla PHP) we're dealing with > here? By the way, I can tell you that in real world applications we did > not manage to measure any performance gain from the realpath cache, even > though we measured 35% performance improvement in a synthetic test, and I > expect it to be quite similar with this patch. Before we introduce such a > big potential for breakage at the fingertips of every user, let's be sure > it's worth it.
It depends completely on your operating system. Benchmark an application on FreeBSD 4.x that has a lot of includes and you can't miss it. My standard benchmark, which doesn't actually do very many file ops went from 161 requests/second to 195 requests/second with this patch. On operating systems like Linux where syscalls are much lighter, you won't see anywhere near that. But you are still going to see a difference. If you couldn't measure a performance gain then it was lost in some serious other noise in your test. You will typically go from something like 120 stats, seeks and ftells down to 8 or 9 per request with the patch. And by the way, include_once doesn't completely break. It will still catch multiple includes of the same path which is usually what people are interested in. It just won't catch something like: include_once 'file.inc'; include_once '../dir/file.inc'; assuming file.inc is in 'dir'. And while that is significant, in deployments where you have full control over the code or the ability to just whack people and tell them not to do stupid stuff like that, it becomes a non-issue. -Rasmus -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
