atomic operations under linux

[guy keren]

who's handling the memory barriers - do all the __sync_* functions 
perform an internal memory barrier operation (on the CPU _and_ on the 
compiler)?

--guy

Raz wrote:
> Do not use inline kernel atomic_t operation, you will violate GPL.
> Use gcc builtins. If you want information please refer to:
> http://sos-linux.svn.sourceforge.net/viewvc/sos-linux/offsched/Linux-Debug/
> and download linux-debug.pdf . You will few words on atomicity in user 
> space in linux.
> Please execuse for bad editing, the paper is not complete.
> 
> raz
> 
> 
> On Wed, Dec 9, 2009 at 6:45 PM, Gilboa Davara <gilboad at gmail.com 
> <mailto:gilboad at gmail.com>> wrote:
> 
>     On Wed, 2009-12-09 at 18:22 +0200, Erez D wrote:
>      > hi
>      >
>      > hi do i do atomic operations in linux (userspace) ?
>      >
>      > i need somthing like testAndSet32()
>      >
>      >
>      > thanks,
>      > erez.
> 
>     You could access the kernel's atomic in-line function from user-space.
>     (under /usr/src/linux/arch...)
> 
>     You'll have to include half kernel to satisfy missing symbols - but it's
>     doable. (At least it worked, last time I tried.)
> 
>     Oh, I remember alsa (-devel) having a copy of these headers in a
>     user-mode digest-able form. Not sure though.
> 
>     - Gilboa
> 
> 
> 
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