The following reply was made to PR general/2669; it has been noted by GNATS.
From: Josh Beck <[EMAIL PROTECTED]> To: Marc Slemko <[EMAIL PROTECTED]> Cc: [EMAIL PROTECTED] Subject: Re: general/2669: Files being served are loaded into memory then served Date: Wed, 22 Jul 1998 17:54:34 -0700 (PDT) > Yes, Apache uses mmap(). If you want to disable it, remove the > USE_MMAP_FILES define from the appropriate section of the include/conf.h > file. > > However, if you think you want to stop it from using mmap() then you are > probably wrong, especially on FreeBSD. You will not magically gain the > amount of memory listed by ps or top by stopping using mmap(). No, I don't plan on gaining that much back, and buying more memory isn't a problem. What I'd like to do is avoid the problem we may encounter when there are downloads of 200 simultaneous (different) songs going on, say, where we would need 1GB of ram to mmap all the files so they can be served simultaneously. Yes, we can buy 1 GB or ram, but that stops becoming a valid solution really quickly, as the price of machine and the ram for a machine that can handle that much memory are very high. Something else I just thought of is that the problem isn't helped by splitting downloads across multiple machines, as each machine would need an equal amount of ram. :( I mean, we can buy 512 M or 1 G of ram for one PC, or for several, but we can't just go out and buy a Sparc or something with 10 G of ram simply to fit all files currently being downloaded into memory. If I stop using mmap, I imagine that there would be performance issues introduced in that more disk accesses would be required to keep the buffer cache up to date (particularly with different instances of apache serving different portions of any specific file), but if this is a lesser problem than the issues caused by mmap(), are there any reasons not to do this? Josh Beck [EMAIL PROTECTED] =========================================================================== http://www.filez.com - Web's largest software search site (75M files!) http://www.mp3.com - #1 music site on the web, ultimate MP3 resource! http://www.websitez.com - Find domain names easier & faster than whois!
