Req #73887 [Com]: Improve realpath cache eviction strategy

Edit report at https://bugs.php.net/bug.php?id=73887&edit=1 ID: 73887 Comment by: spam2 at rhsoft dot net Reported by: maggus dot staab at gmail dot com Summary: Improve realpath cache eviction strategy Status: Open Type: Feature/Change Request Package: Performance problem PHP Version: any Block user comment: N Private report: N New Comment: first it would be much more important to have the cache shared between workers and so fix the split-brain and overhead of maintaining a cache for every process with a very bad hitrate on mahines with hundrets of workers see https://bugs.php.net/bug.php?id=73888 - "We recently changed the default realpath cache" is a big mistake as long as verey single worker has it's own cache with that size and clearstatcache() after change a file don't work at all with the current design Previous Comments: ------------------------------------------------------------------------ [2017-01-07 13:45:40] maggus dot staab at gmail dot com Description: ------------ We recently changed the default realpath cache size as we realized that the default size is too small, see https://github.com/php/php-src/pull/2271. After a closer look into the realpath cache impl krakjoe and bwoebi mentioned, that cache eviction of this cache is very suboptiomal. Cache items are only evicted after a find. Entries never get evicted when no longer used. Php is forced todo some expensive file-io operations when the realpath cache cannot deliver the information from memory. This is especially expensive for long running php scripts, like cli based processes/webservers/... A first improvement would be some kind garbage collection, which isnt bound to a previous find. 2nd the cache could benefit from some kind of LRU cache. 3rd krakjoe mentioned that it might be sometimes usefull to share the cache information in shm. Related discussion: http://chat.stackoverflow.com/transcript/message/34952738#34952738 Starting 5:32 PM ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=73887&edit=1