Re: buddy system

From: Kasper Dupont (kasperd_at_daimi.au.dk)
Date: 03/17/04 

Date: Wed, 17 Mar 2004 08:07:30 +0100

chrismiceli wrote:
>
> I am reading "Understanding the Linux Kernel" (2nd edition) and they
> are describing the buddy system for allocating contiguous blocks of
> memory. I mustn't be grasping the system, could someone explain it to
> me. A good resource would be nice as well describing the buddy system.
> Thanx in advanced.

It is quite simple. Memory allocation is done in
chunks of 2^n pages of alligned memory. Where n
can be anything from 0 to some upper limit.

There is a free list for each n, and each time a
chunk has been released, there is exactly one
possible other chunk of the same size it could be
joined with.

In case there is no free chunks of a specific size,
a larger allocation can be split in two. 

-- 
Kasper Dupont -- der bruger for meget tid paa usenet.
For sending spam use mailto:aaarep@daimi.au.dk
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