Re: [PATCH] Document Linux's memory barriers [try #4]

[David Howells]

Sergei Organov <osv@xxxxxxxxx> wrote:

> > +In addition, accesses to "volatile" memory locations and volatile asm
> > +statements act as implicit compiler barriers.
> 
> This last statement seems to contradict with what GCC manual says about
> volatile asm statements:

Perhaps I should say "compiler memory barrier", since it doesn't prevent
instructions from being moved, but rather merely affects the ordering of
memory accesses and volatile instructions.

Hmmm... Is atomic_read() a compiler memory barrier? It isn't a CPU memory
barrier, but it does touch explicitly volatile memory.

David
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