Stas Bekman wrote: > Moreover the memory doesn't > get unshared > when the parent pages are paged out, it's the reporting tools that > report the wrong > information and of course mislead the the size limiting modules which > start killing > the processes.
Apache::SizeLimit just reads /proc on Linux. Is that going to report a shared page as an unshared page if it has been swapped out? Of course you can void these issues if you tune your machine not to swap. The trick is, you really have to tune it for the worst case, i.e. look at the memory usage while beating it to a pulp with httperf or http_load and tune for that. That will result in MaxClients and memory limit settings that underutilize the machine when things aren't so busy. At one point I was thinking of trying to dynamically adjust memory limits to allow processes to get much bigger when things are slow on the machine (giving better performance for the people who are on at that time), but I never thought of a good way to do it. - Perrin
