Being written in Python, DWiki uses a certain amount of object orienteddesign (not huge amounts; it has basically no inheritance hierarchyamong its classes, although they have various interrelations). Inparticular, it has a Page class that represents a particular real pageat the model level (not the presentation level, which is where templateprocessing and so on happens).

Here is a trick question: is a page's URL a property of the page?(That is, should the Page class have a url

Following up yesterday's entry on the general background of system virtual memory limits, here's howLinux deals with this issue. In its traditional way, Linux gives youthree options for what happens when a process tries to allocate somemore memory, controlled by the value of the vm.overcommit_memory sysctl:

• the kernel gives you the memory unless it thinks you would clearlyovercommit the system (mode 0, the default, 'heuristic overcommit').

• the kernel always gives you the memory (mode 1

First, a definition: the committed address space is the total amountof virtual memory that the kernel might have to supply real memory pagesfor, either in swap space or in RAM. In other words, this is how muchmemory the kernel has committed to supplying to programs if they alldecide to touch all of the memory they've requested from the kernel.

(This is less than the total amount of virtual memory used in thesystem, since some things, like program code and memory mapped files,don