Re: [PATCH v3 1/2] qspinlock: Introducing a 4-byte queue spinlockimplementation

[Rik van Riel]

On 01/28/2014 01:19 PM, Waiman Long wrote:
> This patch introduces a new queue spinlock implementation that can
> serve as an alternative to the default ticket spinlock. Compared with
> the ticket spinlock, this queue spinlock should be almost as fair as
> the ticket spinlock. It has about the same speed in single-thread and
> it can be much faster in high contention situations. Only in light to
> moderate contention where the average queue depth is around 1-2 will
> this queue spinlock be potentially a bit slower due to the higher
> slowpath overhead.
>
> This queue spinlock is especially suit to NUMA machines with a large
> number of cores as the chance of spinlock contention is much higher
> in those machines. The cost of contention is also higher because of
> slower inter-node memory traffic.

> Signed-off-by: Waiman Long <Waiman.Long@xxxxxx>

Acked-by: Rik van Riel <riel@xxxxxxxxxx>

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