Messages in this thread | | | Subject | Re: [PATCH 00/12] perf_events: add support for sampling taken branches (v2) | From | Peter Zijlstra <> | Date | Tue, 06 Dec 2011 12:03:32 +0100 |
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On Tue, 2011-12-06 at 09:49 +0000, Will Deacon wrote: > On Mon, Dec 05, 2011 at 10:39:26PM +0000, Peter Zijlstra wrote: > > On Fri, 2011-10-14 at 14:37 +0200, Stephane Eranian wrote: > > > This patchset adds an important and useful new feature to > > > perf_events: branch stack sampling. In other words, the > > > ability to capture taken branches into each sample. > > > > > Other than the few comments given it all looks good. My main worry is > > the Intel only aspect, I'd really love for there to be another platform > > that could implement at least part of this. > > I discussed this with Stephane in Prague and, although it would be lovely to > have this on ARM, we simply don't have the hardware to do it. So the nature > of series does seem to be x86-centric unless there's way to do a watered > down version in software.
The only way to do this in software would be like CONFIG_PROFILE_ALL_BRANCHES and that's horrid (and kernel only).
But there's more than Intel & ARM, but it looks like PPC doesn't have this either and I suspect MIPS and SPARC don't either, which doesn't leave us with much else.
So I guess we should just go ahead and merge this and hope more hardware grows this feature in a compatible enough manner.
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