Subject: Re: [thiscpuops upgrade 10/10] Lockless (and preemptless)
 fastpaths for slub
From: Peter Zijlstra <peterz@infradead.org>
To: Christoph Lameter <cl@linux.com>
Cc: akpm@linux-foundation.org, Pekka Enberg <penberg@cs.helsinki.fi>,
        Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Tejun Heo <tj@kernel.org>
In-Reply-To: <20101123235201.758191189@linux.com>
References: <20101123235139.908255844@linux.com>
	 <20101123235201.758191189@linux.com>
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Date: Wed, 24 Nov 2010 09:15:12 +0100
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On Tue, 2010-11-23 at 17:51 -0600, Christoph Lameter wrote:
> So there is no need even to disable preemption which will make the allocations
> scale well in a RT environment. 

The RT thing isn't particularly about scaling per-se, its mostly about
working at all.

This thing still relies on disabling IRQs in the slow path, which means
its still going to be a lot of work to make it work on -rt.

It also heavily relies on bit-spinlocks, which again is going to need
changes for -rt.

But yes, the lockless fast path is nice, I'll try and get around to
reading it.
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