Messages in this thread | | | Date | Fri, 11 Dec 2015 23:39:30 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH v0 3/5] perf: Introduce instruction trace filtering |
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On Fri, Dec 11, 2015 at 07:13:10PM +0200, Alexander Shishkin wrote: > Peter Zijlstra <peterz@infradead.org> writes: > > On second thought; we should not inherit the filters at all. > > > > We should always use event->parent (if exists) for filters. Otherwise > > inherited events will get different filters if you change the filter > > after clone. > > But children will have different mappings,
_can_ have.
> so the actual filter > configurations will still differ between parents and children. I guess I > could split the filter in two parts: one that's defined by the user and > one that we calculated from vma addresses, that we later program into > hardware.
/me confused, isn't that what you already do?
In any case, since inherited counters are uncontrollable (they have no filedesc of their own) and you cannot a priory tell what a child will go do, let alone a child of a child. It really makes no sense to have different filters on different parts of the inherited tree.
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