Messages in this thread | | | Date | Sat, 30 Apr 2011 17:03:51 -0400 (EDT) | From | Vince Weaver <> | Subject | Re: re-enable Nehalem raw Offcore-Events support |
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On Sat, 30 Apr 2011, Borislav Petkov wrote: > On Fri, Apr 29, 2011 at 10:17:04PM -0400, Vince Weaver wrote:
> > Well guess what, AMD family 15h changes all of that. > > I don't see a big problem here, Robert has a patch that takes care of > counter constraints. It probably needs a bit more work but we'll get > where we need to be.
yes, but it's a bit of a change from the PMU of previous AMD chips, going against Ingo's argument that the featureset of all modern CPUs is somehow converging.
> > And you're not going to like LWP. They got tired of waiting for a > > workable kernel perf counter interface and moved it completely to > > usersapce, > > I don't know where you get your information but that's absolutely and > completely not nearly even beginning to smell the truth.
I talked with someone fairly involved in the development with LWP who implied as much in an off-the-record discussion. You have to admit back 5-6 years old when LWP was being planned it wasn't certain that kernel support for perf events was *ever* going to make it into Linux. Though maybe AMD is more concerned about the even worse support in other OSes. It's true you'd probably know better.
> Look at tip/x86/xsave, looks like LWP support will most likely be in > 2.6.40.
Really? Does Ingo know yet? I get the impression he doesn't like perf-event features slipping in under the radar like that.
Vince
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