Messages in this thread | | | Date | Tue, 27 Mar 2018 02:06:42 -0700 | From | Andi Kleen <> | Subject | Re: [PATCH v1] perf stat: avoid 10ms limit for printing event counts |
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> When running perf stat -I for monitoring e.g. PCIe uncore counters and > at the same time profiling some I/O workload by perf record e.g. for > cpu-cycles and context switches, it is then possible to build and > observe good-enough consolidated CPU/OS/IO(Uncore) performance picture > for that workload.
At some point I still hope we can make uncore measurements in perf record work. Kan tried at some point to allow multiple PMUs in a group, but was not successfull. But perhaps we can sample them from a software event instead.
> > The warning on possible runtime overhead is still preserved, however > it is only visible when specifying -v option.
I would print it unconditionally. Very few people use -v.
BTW better of course would be to occasionally measure the perf stat cpu time and only print the warning if it's above some percentage of a CPU. But that would be much more work.
Rest looks ok.
-Andi
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