On Fri, Jul 17, 2015 at 08:57:00PM +0800, pi3orama wrote: > >> But what if we really want cross-cpu PMU accessing? Impossible? > > > > Under the assumption that the eBPF program is called from tracing, and > > therefore from any context (task, softirq, irq and nmi), yes impossible. > > > > You cannot do (synchronous) IPIs from either IRQ context or with IRQs > > disabled. And both are valid trace contexts. > > What about software perf event? For example, tracepoints?
Some of them, tracepoints would work. So you could exempt TYPE_TRACEPOINT, but I would suggest starting as constrained as possible and relaxing when we really need/want. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
