Re: PEBS level 2/3 breaks dwarf unwinding! [WAS: Re: Broken dwarf unwinding - wrong stack pointer register value?]

[Andi Kleen]

> hum, is this about having 'large pebs' or there's this window
> if there's also only single pebs record allowed? which should
> be case for dwarf unwind

With large PEBS today there is never any stack unwind because
stack unwinding can be only done from a PMI.

The window happens even with single PEBS. It's related
to the CPU being pipelined, so complex events may not
happen fully atomically.

-Andi