Linux Kernel Mailing List FAQ

One page I had not noticed, and which seems to contain lots of interesting features: the Linux Kernel Mailing List FAQ. There are some nice infos for newbies... But not so much information except a lot of very nice pointers to different useful places.

Linux Kernel: Copy on Write

Copy on Write is an important technique in the linux kernel memory management. The basic idea is to prevent the creation of unnecessary copies of structures when creating new processes. For this, when a child process is created, the kernel first provides only readable access to both parent and son. If one of the process need writable access, at the time it needs to write data in memory, the kernel throws a page fault indicating that a new copy should be created for the asking process. Thus, the data is actually copied only when the process actually tries to write.

Some information is of course available on Wikipedia on the Copy on Write page. Note that there is an acronym COW for Copy on Write.

Memory Management Documentation in Linux Kernel

As I was looking at the kernel newbies info. I found this post from Mel Gorman about documentation for the Memory Management under Linux. It contains links to two documents:

• Understanding The Linux Virtual Memory Manager
• Code Commentary On The Linux Virtual Memory Manager