Bug 199697

Summary: Perf record of mem event on kernel data address causing freeze
Product: Tracing/Profiling Reporter: Probir Roy (proy)
Component: Kernel PerfAssignee: Frederic Weisbecker (fweisbec)
Status: NEW ---    
Severity: normal CC: a.p.zijlstra
Priority: P1    
Hardware: Intel   
OS: Linux   
Kernel Version: Linux version 4.15.0-rc4 Subsystem:
Regression: No Bisected commit-id:
Attachments: Detailts on system information
config file

Description Probir Roy 2018-05-11 17:05:53 UTC 
Created attachment 275925 [details]
Detailts on system information

I am using perf-tool to record memory access to some kernel addresses. For some kernel addresses it freezes/lockup the system.

I am using kernel version 4.15.0 on x86_64 arch. I am running on an Intel Broadwell machine.

I am using Intel's PEBS to sample kernel memory access while running a micro-benchmark (performs repeated file operation) using following command.

$ sudo perf mem -t store record

This records memory references. After that I run a script to set HW breakpoint at the reference addresses.

$ sudo timeout 1s perf record -e mem:<0xaddress>:rw

It causes system hang at some address (for many address perf reports correctly). Nothing is written in kern.log
Comment 1 Probir Roy 2018-05-11 18:10:20 UTC 
Created attachment 275931 [details]
config file