Subject: Re: Fwd: Located problem in pcn driver...
To: der Mouse <mouse@Rodents.Montreal.QC.CA>
From: Kamal R Prasad <>
List: tech-kern
Date: 04/21/2003 06:48:15

Kamal R. Prasad
AIX Support & Test, IBM India Software Labs
Golden Enclave, Airport Road, Bangalore-560017, India
Phone : +91-80-5094963,  Internal Ext   : 2963

> [...] logic [...] to decide if it(load/store) is meant for I/O device
> or memory and probably bypasses cache as a result for I/O operations
> without the volatile keyword being used.

>The volatile keyword has nothing to do with bypassing cache in the
>memory-subsystem sense; it exists to prevent the compiler from cacheing
>"stored" values, optimizing it away, rearranging it with respect to
>other volatile-marked stores, or suchlike.

yes -that was my messup.  the volatile keyword exists to prevent the
compiler from optimizing the generated code (under the presumption that it
is general memory and/or that the memory contents can be modified by the
cpu only).

/~\ The ASCII                                                der Mouse
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