Re: [PATCH 8/5] llist: Remove cpu_relax() usage in cmpxchg loops

From: Andi Kleen
Date: Mon Sep 12 2011 - 12:38:50 EST


> so basically, in typical locking primitives (spinlock), it looks like
> lower power consumption is preferred over getting the raw maximal

It's not only power, its:
- Allow the other siblings make more progress on SMT
- Do some backoff to stress the interconnect less (this is important on >2S):
A tight loop which constantly writes is a extremly stressfull pattern.
- Save some power by allowing the CPU to do more clock gating

-Andi
--
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/