[RFC] implement QUEUED spinlocks on powerpc
edumazet at google.com
Thu Feb 2 15:40:51 AEDT 2017
On Wed, Feb 1, 2017 at 8:04 PM, Michael Ellerman <mpe at ellerman.id.au> wrote:
> Benjamin Herrenschmidt <benh at kernel.crashing.org> writes:
>> On Wed, 2017-02-01 at 09:05 -0800, Eric Dumazet wrote:
>>> Hi all
>>> Is anybody working on adding QUEUED spinlocks to powerpc 64bit ?
>>> I've seen past attempts with ticket spinlocks
>>> ( https://patchwork.ozlabs.org/patch/449381/ and other related links
>>> But it looks ticket spinlocks are a thing of the past.
>> Yes, we have a tentative implementation of qspinlock and pv variants:
>> Michael, what's the status with getting that merged ?
> Needs a good review, and the benchmark results were not all that
> compelling - though perhaps they were just the wrong benchmarks.
A typical benchmark would be to use 200 concurrent netperf -t TCP_RR,
through a single qdisc (protected by a spinlock)
Non ticket/queued spinlocks behave quite bad in this scenario.
I can try this next week if you want.
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