Re: [patch 01/23] Fall back on interrupt disable in cmpxchg8b on 80386 and 80486

* Christoph Lameter (clameter@xxxxxxx) wrote:
On Mon, 20 Aug 2007, Mathieu Desnoyers wrote:

Yes, I use it as synchronization mechanism for my buffer management algorithm
in LTTng. Since I write in per-cpu buffers and want to be as reentrant
as possible wrt other contexts (dealing with NMI as worse case, but also
applies to MCE..), I use local_cmpxchg to reserve space in my buffers.
It is faster than the standard cmpxchg.

Ok I have seen these numbers in the OLS papers but I could not reproduce
them in SLUB.


I'm digging in the slub with cmpxchg_local patch... first detail:
slab_alloc seems to have a return path that does not reenable
preemption... I'll keep you posted when I finish the 2.6.23-rc2-mm2
port.

Mathieu

--
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/