RE: [Fwd: [Ltt-dev] MIPS atomic operations, "sync"]

["Kaz Kylheku" <kaz@zeugmasystems.com>]

Sergei Shtylyov wrote:
> I just came across the MIPS atomic.h and system.h 
> implementations in 2.6.18
> which brings a question :
> 
> Why are the primitives in include/asm-mips/atomic.h using the "sync"
> instruction even in the UP case ? system.h cmpxchg only uses 
> the sync in the
> SMP case.

There was just a discussion about this in the mailing list. Check the
archive.

Ralf Baechle mentioned that he has a patch to remove the syncs from
uniprocessor code, so that would seem to answer your question.

Thread subject line: "Sync operation in atomic_add_return()".