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> 在 2015年7月17日，下午9:26，Peter Zijlstra <[email protected]> 写道： > > 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. > > Thanks to your advise. We will follow them in v2. Do you have further comment on other part of this patch set? Thank you. -- 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/
