Basic cache questions

[Steve Taylor <godzilla1357@yahoo.com>]

Hello All,

 

  I am hoping some of you mips-linux gurus will be able to help me give me some tips and help me get started on some cache stuff which I want to do. (I know decently well about caches - but only at a theoretical Hennessy & Patterson level - and have just started looking under arch/mips/mm to familiarize myself with the mips-linux implementation).

 

  Here's what I want to do - I have a CPU with 4 way SA I and D caches, and I want to write a module that will lock a certain memory region in these caches (for example, let's say I want to lock the ISR in the I-cache). So my questions are a) Is the kernel going to crash if I try to mess around with the caches like locking out a particular way of the cache or something like that? b) I'm sure there are many issues and complications involved in this that I probably havent even thought of  - any obvious and/or subtle pitfalls? and c) Do you think locking out, say, an entire way of a 4-way cache for a dedicated frequently used routine improves or degrades overall system performance? 

 

 TIA,

 

-Steve.

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