Red Hat Bugzilla – Bug 220821
Default PHP memory_limit should be increased on 64-bit platforms
Last modified: 2007-11-30 17:11:52 EST
Because 64-bit pointers & longs take up more memory, larger PHP scripts will not run successfully on 64-bit platforms with default PHP configuration, even though the same configuration allows them to run on 32-bit platforms. This is because the memory_limit setting in /etc/php.ini is the same on both 32-bit and 64-bit platforms. The memory limit on 64-bit platforms should be 1.5x to 2x the limit on 32-bit platforms.
We've had fewer reports of memory_limit issues since the default was bumped to 16M everywhere (FC6) - were you still seeing this type of problem with the 16M default?
Yes; I had to bump the limit up to 32M to get things to work on x86_64. On i386, 16M seems to work OK, and I'm sure that limit is more than enough for most people. The main point I was making was that if the limit is N megabytes on a 32-bit platform, it should be N*2 megabytes on a 64-bit platform.
Using the N*2 value as one-size-works-everywhere is simpler; 32M seems a reasonable stab in the dark; upstream bumped to 128M which seems too high. This was done in Raw Hide, thanks for the report.