Messages in this thread | | | Date | Sat, 26 Jan 2013 22:00:00 +0100 | From | Andi Kleen <> | Subject | Re: [PATCH 04/12] perf, x86: Support the TSX intx/intx_cp qualifiers v2 |
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On Sat, Jan 26, 2013 at 12:54:02PM +0100, Ingo Molnar wrote: > > * Andi Kleen <andi@firstfloor.org> wrote: > > > From: Andi Kleen <ak@linux.intel.com> > > > > Implement the TSX transaction and checkpointed transaction > > qualifiers for Haswell. This allows e.g. to profile the number > > of cycles in transactions. > > The changelog should explain why this is a basic feature that is > a must-have to have basic perf support. (i.e. default 'perf > record', 'perf report', 'perf stat' and 'perf top' works and is > meaningful.)
The patch is not needed for primitive cycle sampling only.
These qualifiers are a fundamental feature for any TSX tuning. If you don't care about TSX it's not fundamental. TSX tuning relies heavily on the PMU, so for any TSX work it's important. The 0/0 description has more references on the topic.
It's not easy to use however with just this patch, the "perf stat -T" patch in the advanced series makes it easy to use.
I will assume the description is sufficient and will not repost with a new changelog, as "basicness" of the patch is not a useful property to document in the long term git history.
-Andi -- ak@linux.intel.com -- Speaking for myself only.
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