gcc 4.1 implements compiler builtins for atomic ops

Benjamin Herrenschmidt benh@kernel.crashing.org
Sun Jun 26 22:55:00 GMT 2005


> We will be working to implement the atomic ops in gcc on parisc.
> 
> For parisc the atomic operation is implemented as a light-weight
> syscall, on the gateway page, consisting of 18 instructions on the fast
> path. Tests show this is as close to optimal as possible. With scaling
> out to ~16 cpus (all on paper though). I could probably re-architect the
> light-weight-syscall locking to scale to higher cpus.
> 
> This has the unfortunate issue of requiring a newer kernel. I'm not sure
> how to handle this type of requirement against gcc. With glibc I could
> use a vDSO or --enable-kernel and some package management entries.

So you are putting vDSO dependencies in gcc ? ugh ?

Am I the only one to think that this is a very bad idea ?

Damn, these things should be in glibc, not the compiler !

Ben.




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