Please tell me if it is possible to lock cache memory of raspberry PI board. If so, what is the procedure.
I'm not shure what cache you mean.
ARM L2 cache: 128kiB; probably not a good idea to disable it, the pi might become awfully slow. From http://elinux.org/RPiconfig : setting
Linux kernel cache: from http://www.commandlinefu.com/commands/view/2888/release-memory-used-by-the-linux-kernel-on-caches :
On 2nd thought, I assume you mean locking cache out, aren't you?
will swap as little as possible; default is 60. Note that I didn't try, I just removed the swapfile.
Edit: The linux kernel automagically assign unused memory pages to system cache, mostly for I/O. This can be write cache to mass storage, which is slow and can benefit a lot of reordering, to get contiguous sectors on a hdd, or to reduce erase block usage on flash based devices (sd card, ssd, usb key, etc). Search lwn.net for gory details about the kernel. (As a newbie here I'm not allowed to post more than 2 links in a post and I already cheated with 2 extra non-URL domain names :)
Again: Linux Weekly News is a good reference for understanding what is linux and how it works. Just try to understand what you can, and skip what makes you sick at a glance.
Hope this helps, at least for you to get a more precise question;)