> Even if you ignore the fundamental semantics of groups, there are other > problems with allowing shared contexts: > > * The *_txn functions only get called on the group leader's PMU. If your > system PMU has these functions, they are not called. > > * Event rotation is per ctx, but now you could have some events in a CPU > PMU's context, and some in the uncore PMU's context. So those can race > with each other. > > * Throttling is also per-context. So those can race with each other too.
There's also a break down of behaviour: events in the uncore context will get migrated to another CPU in the event of a hot unplug, while events that are grouped with CPU events (and hence live in the CPU context) will be destroyed. Mark. -- 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/
