Messages in this thread | | | Date | Mon, 20 Aug 2007 17:29:22 -0400 | From | Mathieu Desnoyers <> | Subject | Re: [patch 01/23] Fall back on interrupt disable in cmpxchg8b on 80386 and 80486 |
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* Christoph Lameter (clameter@sgi.com) 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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