After a bit more investigation, I would like to change this paragraph: Once a script finishes executing, although the garbage collector technically has freed the ram, the pages are still allocated. The next time the thread executes, there is a whole pile of swapping and if a memory hungry script gets run again, the memory footprint increases.
To: Once a script finishes executing, although the garbage collector technically has freed the ram, the pages are still allocated. If the thread is re-used, even for a small script, much of the previously swapped out ram is swapped back in due to fragmentation. The memory footprint of the thread will increase further if a different memory hungry script is executed, or a small script that has a different allocation pattern to the first memory eating script is executed. Regards, ap. On Sat, June 11, 2005 16:30, Andrew Prendergast said: > Hey Folks, > > I'm not on the list so please reply back to my email. > > I have been having some problems with memory fragmentation in PHP when > working with large data structures. > > Once a script finishes executing, although the garbage collector > technically has freed the ram, the pages are still allocated. The next > time the thread executes, there is a whole pile of swapping and if a > memory hungry script gets run again, the memory footprint increases. > > Now consider what happens when I have 20 processes in an FCGI pool, each > one getting above 300MB in size, its not good. > > My solution which I have implemented as part of the FCGI SAPI (thanks to > GeorgeS, hartmut, Pierre & Derick for their guidance) is the introduction > of two new environment variables, PHP_FCGI_MAX_RAM_MB & > PHP_FCGI_MAX_RAM_INCREASE. > > PHP_FCGI_MAX_RAM_MB allows one to set a limit (in megabytes) of how large > an FCGI process is allowed to grow to. > > PHP_FCGI_MAX_RAM_INCREASE allows one to set a maximum % increase compared > to when the process first started. > > If either of these limits are exceeded, the process will be restarted > AFTER script execution has completed (unlike the --enable-memory-limit > stuff). > > Please get back to me on: > > 1. your thoughts on this > > 2. an idea of how big an average PHP process should be (mine are 150MB > when they start, 160MB after running some average scripts, and grow to > above 300 MB when working with big data structures and complex object > caching code) > > 3. how do i get this back into the PHP source tree! (sorry newbie) > > Regards, > > ap. > > -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
