Re: [PATCH -v4 3/5] x86,smp: auto tune spinlock backoff delay factor

2013-01-26 Thread Ingo Molnar
* Rik van Riel wrote: > Many spinlocks are embedded in data structures; having many CPUs > pounce on the cache line the lock is in will slow down the lock > holder, and can cause system performance to fall off a cliff. > > The paper "Non-scalable locks are dangerous" is a good reference: > >

[PATCH -v4 3/5] x86,smp: auto tune spinlock backoff delay factor

2013-01-25 Thread Rik van Riel
Many spinlocks are embedded in data structures; having many CPUs pounce on the cache line the lock is in will slow down the lock holder, and can cause system performance to fall off a cliff. The paper "Non-scalable locks are dangerous" is a good reference: http://pdos.csail.mit.edu/papers