On Wednesday 17 June 2015 07:03 PM, Peter Zijlstra wrote: >> But in case of raw events we need to set a counter with index of a >> > particular event. For example we need to count "myevnt0" events. For >> > this we need first to find-out what's an index in events list of >> > "myevnt0" event and then set event counter to count event #x. >> > >> > Even though in theory we may set raw even passing an index of desired >> > event > That is what I was thinking of, until I read: > >> > but given my explanation above each particular CPU may have the >> > same event with different index in events list. > ... > >> > Fortunately there's already a patch series floating in LKML that >> > attempts to simplify usage of architecture-specific events, see >> > http://www.spinics.net/lists/kernel/msg2010232.html > So you _can_ know a priory in which order the events are for a > particular CPU ? Say through /proc/cpuinfo. > > I would much prefer the raw thing to remain a number; it puts you in > pretty much the same place as most other archs, including x86. Sure, but that doesn't mean we start using the index of event as a raw ID. There are zillion ways to configure cores and the index will certainly start varying. Which means that user has to determine at run time (using whatever /proc/xxx) what crun corresponds to. Why inflict such pain on poor guy. The current raw event, despite representing an ASCII string is still a u64 number. So it is not more "raw" than what others have. We can get rid of the swapping business when setting up a raw event, by making sure that cached values from probe are already in same format. But using index as a event id is no go sorry... > > On x86 we have a huge event list (see the Intel SDM for example) and the > only way to access those (currently, without the above patch series) is > to look in the PDF under the right model and enter the numbers by hand. It is not much different for us ! > The only way in which your hardware appears different is in that it > seems to include these names in hardware; which to me seems a waste of > perfectly fine silicon, but hey not my call. Yeah sins of the past.... :-) -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
