Messages in this thread | | | Date | Sun, 15 Jun 2014 15:16:54 +0200 | From | Peter Zijlstra <> | Subject | Re: [PATCH v11 14/16] pvqspinlock: Add qspinlock para-virtualization support |
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On Thu, Jun 12, 2014 at 04:48:41PM -0400, Waiman Long wrote: > I don't have a good understanding of the kernel alternatives mechanism.
I didn't either; I do now, cost me a whole day reading up on alternative/paravirt code patching.
See the patches I just send out; I got the 'native' case with paravirt enabled to be one NOP worse than the native case without paravirt -- for queue_spin_unlock.
The lock slowpath is several nops and some pointless movs more expensive.
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