Re: lockdep oddity

Ingo Molnar
2006-09-06T08:48:41Z

* Hua Zhong <hzhong@gmail.com> wrote:

> We are just trading accuracy for speed here.

no, we are trading _both_ accuracy and speed here! a global 'likeliness'
pointer for commonly executed codepaths is causing global cacheline
ping-pongs - which is as bad as it gets.

the right approach, which incidentally would also be perfectly accurate,
is to store an alloc_percpu()-ed pointer at the call site, not the
counter itself.

the current code needs more work before it can go upstream i think.

Ingo