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Memory Allocation

Issue 16

From Issue #16
August 1995

Aug 01, 1995  By Michael K. Johnson
 in
Memory allocation of some sort is required in practically any program, but in the Linux kernel it is more complex than in user-lever code—for good reason.
Memory initialization

This particular method is extremely deprecated, and is architecture-dependent as well. It is possible to add a function call within the body of mem_init(), which resides, for the i86 platform, in the file arch/i386/mm/init.c. In the middle of this function, two functions for initializing SCSI and sound-driver memory are provided. Also, arch/i386/kernel/head.S provides another platform-dependent way to allocate memory. This is where initial memory management is set up.

If you understand these well enough to muck with them, you don't need my help. These are last resorts for memory allocation, and you need to know exactly what you need to do, and why the dynamic allocation strategies will not work for you, before considering these “hacks”.

Michael K. Johnson is the Editor of Linux Journal, and pretends to be a Linux guru in his spare time. He can be reached via email as johnsonm@ssc.com.

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Kb or KB?

Anonymous's picture
Submitted by Anonymous on Wed, 03/10/2010 - 04:36.

I believe the PAGE_SIZE is usually in Bytes not bits. Please correct me if I am wrong.

Yes, bytes

Mitch Frazier's picture
Submitted by Mitch Frazier on Wed, 03/10/2010 - 11:10.

Page size is given in bytes. The article isn't saying it's in bits, it just uses Kb when it should have used "KB".

Mitch Frazier is an Associate Editor for Linux Journal.

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