Re: [RFC][PATCH 0/7] locking: qspinlock

[Ingo Molnar <mingo@kernel.org>]

* Peter Zijlstra <peterz@infradead.org> wrote:

> Hi Waiman,
> 
> I promised you this series a number of days ago; sorry for the delay 
> I've been somewhat unwell :/
> 
> That said, these few patches start with a (hopefully) simple and 
> correct form of the queue spinlock, and then gradually build upon 
> it, explaining each optimization as we go.
> 
> Having these optimizations as separate patches helps twofold; 
> firstly it makes one aware of which exact optimizations were done, 
> and secondly it allows one to proove or disprove any one step; 
> seeing how they should be mostly identity transforms.
> 
> The resulting code is near to what you posted I think; however it 
> has one atomic op less in the pending wait-acquire case for NR_CPUS 
> != huge. It also doesn't do lock stealing; its still perfectly fair 
> afaict.
> 
> Have I missed any tricks from your code?

Waiman, you indicated in the other thread that these look good to you, 
right? If so then I can queue them up so that they form a base for 
further work.

It would be nice to have per patch performance measurements though ... 
this split-up structure really enables that rather nicely.

Thanks,

	Ingo