[Bug 1730782] Re: [Bug] [KNL] ~5x slowdown of application when attaching by perf on KNL

No special request for bionic. Just for 18.10 will be enough.

only one is provided. Other 3 patches are not found. Upstream tested it
that has been fixed.

https://www.spinics.net/lists/kernel/msg2552460.html

commit 8e1a2031e4b556b01ca53cd1fb2d83d811a6605b
Author: Alexey Budankov <alexey.budankov@linux.intel.com>
Date: Fri Sep 8 11:47:03 2017 +0300

perf/cor: Use RB trees for pinned/flexible groups

Change event groups into RB trees sorted by CPU and then by a 64bit
index, so that multiplexing hrtimer interrupt handler would be able
skipping to the current CPU's list and ignore groups allocated for the
other CPUs.

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Title:
[Bug] [KNL] ~5x slowdown of application when attaching by perf on KNL

Status in intel:
Fix Released
Status in linux package in Ubuntu:
Triaged
Status in linux source package in Bionic:
Triaged

Bug description:
Description:

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
vs
perf record -a – workload

Patch is submitted for review

https://www.spinics.net/lists/kernel/msg2552460.html
https://www.spinics.net/lists/kernel/msg2552461.html
https://www.spinics.net/lists/kernel/msg2552462.html
https://www.spinics.net/lists/kernel/msg2552463.html

Target kernel: 4.17
Target Release: 18.10

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