On Mon, Jan 06, 2014 at 03:10:28PM -0800, Andi Kleen wrote: > Peter Zijlstra <pet...@infradead.org> writes: > > Also, do clarify the other points I asked about. Esp. the non > > FREEZE_ON_PMI behaviour of the PT PMI is worrying me immensely. > > The only reason for hardware freeze is when you have a few entries (like > with LBRs) so the interrupt entry code could overwhelm it. > > But PT is not small, it's gigantic: even with the smallest buffer you > have many thousands of entries. > > So you will get a few branches in the interrupt entry, but it's not a problem > because everything you really wanted to trace is still there. > > Eventually the handler disables PT, so there's no risk of racing with > the update or anything like that. > > Did I miss anything?
Yes; go read this: lkml.kernel.org/r/20131219125205.gt3...@twins.programming.kicks-ass.net -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
