Subject: [RFC][PATCH 0/7] locking: qspinlock
Date: Monday 10th March 2014 15:42:36 UTC (over 2 years ago)
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? The patches apply to tip/master + email@example.com I've yet to look at the paravirt stuff.