Re: [PATCH 0/24] make atomic_read() behave consistently across all architectures

Christoph Lameter writes:

A volatile default would disable optimizations for atomic_read. 
atomic_read without volatile would allow for full optimization by the 
compiler. Seems that this is what one wants in many cases.

Name one such case.

An atomic_read should do a load from memory.  If the programmer puts
an atomic_read() in the code then the compiler should emit a load for
it, not re-use a value returned by a previous atomic_read.  I do not
believe it would ever be useful for the compiler to collapse two
atomic_read statements into a single load.

Paul.