Re: new multicore programming docs for GCC and Visual Studio

On Sep 29, 5:02=A0pm, "Chris M. Thomasson" <n...@[EMAIL PROTECTED]
> wrote:

> You mean:
>
> 1 atomic RMW and 1 StoreLoad membar for lock
> 1 atomic RMW and 1 LoadStore membar for unlock
>
> 2 atomics, and 2 membars; fairly expensive... Well... You indeed have a
g=
ood
> point in the case that stealing is rare...


No, I mean for spin-mutex:
1 atomic RMW + 1 StoreLoad membar for lock
store-release for unlock

Which for x86 means:
1 atomic RMW for lock (StoreLoad is implied, and so basically
costless)
plain store for unlock (release is implied)


Dmitriy V'jukov