Bug #45644 [Com]: eval() consumes a lot more memory in 64bit system than 32 bit

Edit report at https://bugs.php.net/bug.php?id=45644&edit=1 ID: 45644 Comment by: chris at willowsconsulting dot ie Reported by: trepseb at hotmail dot com Summary: eval() consumes a lot more memory in 64bit system than 32 bit Status: Not a bug Type: Bug Package: Performance problem Operating System: Linux fedora PHP Version: 5.2.6 Assigned To: fb-req-jani Block user comment: N Private report: N New Comment: I became interested by the eval() behavior recently, and I can confirm that the memory usage gets higher by the time of the execution. However it is not really a bug, but the way eval() is fundamentally written: * it creates a temp file with the code inside (sometimes it is stored in memory) * it then includes that temp file using a normal include() function As you can see, the more eval() you do, the more include() it will trigger, resulting in a memory usage that cannot be freed... Previous Comments: ------------------------------------------------------------------------ [2008-07-29 20:46:54] jani@php.net For more info, check bug #41053, bug #40720 which have quite good explanation why this happens. ------------------------------------------------------------------------ [2008-07-29 14:13:09] trepseb at hotmail dot com Thank you jani. This really was an issue with a debugger extension. I still don't understand why the "same" debugger does not have a problem in 32 bit systems and why you would see this as expected behaviour, but it works now. Maybe this is something for the zend people to analyze. Until now must developer systems are not 64 bit and it's very difficult to get to the grounds of this on your server alone. ------------------------------------------------------------------------ [2008-07-28 20:17:54] jani@php.net # uname -a Linux linux5 2.6.20-1.2944.fc6 #1 SMP Tue Apr 10 17:46:00 EDT 2007 x86_64 x86_64 x86_64 GNU/Linux # USE_ZEND_ALLOC=0 php t.php start 8208 end 8208 # USE_ZEND_ALLOC=1 php t.php start 92496 end 223888 # USE_ZEND_ALLOC=1 php -n t.php start 90952 end 94032 Note the last result. The second is with Xdebug enabled. Do you by any chance have Xdebug (or any other Zend extension) loaded? If so, this is quite expected behaviour.. ------------------------------------------------------------------------ [2008-07-28 12:18:41] trepseb at hotmail dot com Description: ------------ We were using eval extensivly for making a dynamic code parser. It used to be all ok till we needed to use it for more than 30000 iterations. Suddenly our memory limit was reached. We tracked it down to the underlying code. Strangely this is only an issue with 64 Bit systems. A PowerMac Dual has this Problem the same as a 8 Core XEON. The INTEL and AMD with 32 bits don't have a Problem, here the script requires no additional memory with each cycle. Probably this has to do with some underlying library, but maybe you can figure out which. Here is a part of my php info Linux ******** 2.6.23.17-88.fc7 #1 SMP Thu May 15 00:02:29 EDT 2008 x86_64 Build Date May 8 2008 08:38:49 Configure Command './configure' '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' '--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--cache-file=../config.cache' '--with-libdir=lib64' '--with-config-file-path=/etc' '--with-config-file-scan-dir=/etc/php.d' '--disable-debug' '--with-pic' '--disable-rpath' '--without-pear' '--with-bz2' '--with-curl' '--with-exec-dir=/usr/bin' '--with-freetype-dir=/usr' '--with-png-dir=/usr' '--enable-gd-native-ttf' '--without-gdbm' '--with-gettext' '--with-gmp' '--with-iconv' '--with-jpeg-dir=/usr' '--with-openssl' '--with-png' '--with-pspell' '--with-expat-dir=/usr' '--with-pcre-regex=/usr' '--with-zlib' '--with-layout=G! NU' '--enable-exif' '--enable-ftp' '--enable-magic-quotes' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--enable-track-vars' '--enable-trans-sid' '--enable-yp' '--enable-wddx' '--with-kerberos' '--enable-ucd-snmp-hack' '--with-unixODBC=shared,/usr' '--enable-memory-limit' '--enable-shmop' '--enable-calendar' '--enable-dbx' '--enable-dio' '--without-mime-magic' '--without-sqlite' '--with-libxml-dir=/usr' '--with-xml' '--with-system-tzdata' '--with-apxs2=/usr/sbin/apxs' '--without-mysql' '--without-gd' '--without-odbc' '--disable-dom' '--disable-dba' '--without-unixODBC' '--disable-pdo' '--disable-xmlreader' '--disable-xmlwriter' '--disable-json' I checked the other eval errors, but they did not have much to do with mine, and they are all stone old ;). Reproduce code: --------------- echo "start ".memory_get_usage()."\n"; $aData['an_anfrage_art'] = '150'; $aData['ega_codes'] = '12|13|15|17|18|23'; for ($i=0;$i<100000;$i++){ eval('$bCondition = !in_array( \'150\' , array(12,13,15,17,18,23));'); } echo "end ".memory_get_usage(); Expected result: ---------------- start 46592 end 47980 32 bit system. This is the expected result the memory usage is constant with more cycles Actual result: -------------- start 78488 end 1710444 64 bit system. Here the memory usage is growing linearly. More cycles make the memory consumption grow. ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=45644&edit=1