Messages in this thread | | | Date | Thu, 25 Jul 2013 23:58:09 -0400 (EDT) | From | Vince Weaver <> | Subject | Re: [PATCH 1/2] tools, perf: Add a precise event qualifier v2 |
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On Wed, 24 Jul 2013, Andi Kleen wrote:
> Sorry I meant flags as an alias of "the 64bits currently occupied by the > bitfield". Perhaps the name choice was not very good. > > "flags_bitfield" ? > > So the tool would only need to know that, not every bit. > > In theory it could be also generalized as a byte offset to perf_event, > but that may be overengineered.
I somehow doubt this would be acceptable. If it were, we could have had a somewhat better interface by just having the event fields be a list of values without involving format/* at all, something like
config=0x58034;config1=0x20;precise_ip=0x4
For whatever reason things have to be human readable, and I don't think just having an opaque 64-bit "flags" value will be accepted.
I'm likely wrong though, I have a very low accuracy rate for predicting future perf_event design decisions.
This is all complicated by the intertwined nature of the perf_event ABI and the perf tool, and the way that there's at least three or four different ways to specify the same event from the perf tool command line.
Vince
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