A v9 was posted on August 31st, but there is still no progress upstream.
Meanwhile, Peter Zijlstra merged
0d3d73aac2ff05c78387aa9dcc2c8aa3804405e7 ("perf/core: Rewrite event
timekeeping"), which looks like would have helped with this problem.
Can you confirm if the latest bionic kernel, which has this commit,
scales better? If not, what is the plan of pushing this forward
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[Bug] [KNL] ~5x slowdown of application when attaching by perf on KNL
Status in intel:
Status in linux package in Ubuntu:
Status in linux source package in Bionic:
Workload slows down for default sampling cycles in KNL. There are some
processing in perf that's single threaded and bottlenecked when number of cores
really go up.
A second issue is that things slow down when we issue
perf record – workload
perf record -a – workload
Patch is submitted for review
Target kernel: TBD
Target Release: 18.04
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