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From: Naruto Nguyen <narutonguyen2018@gmail.com>
To: linux-trace-users@vger.kernel.org
Subject: How to find out which process cause a strange increasing cpu load on a certain core?
Date: Tue, 18 Jun 2019 18:40:13 +0700
Message-ID: <CANpxKHEMjWRSbV8fq_iSR5XAzy7oMuht0xfRTeLtBxajxtW2eg@mail.gmail.com> (raw)

Hello everyone,

I have a kvm hypervisor and setup some VMs running OpenSUSE kernel
4.0. After some reboot, I saw that sometime there is a VM that a
certain core has higher %usr and %sys than other cores. The system is
in ide state. I have some applications running on this VM, but there
is no issue in other VMs.

If I enable ftrace in kernel or load any debug jprobe, the load is
back to normal. The pidstat command output does not show the high load
on one core like the "top" command. Could you please let me know if it
is the problem of "top' report higher usage? Any commands that can
help to troubleshoot this issue? I tried "perf" but most of the time
the perf output does not show any function that cause the increase as
well? Not sure, if the malfunction of top or anything else can add
more work load?

Thanks,
Brs,
Naruto

             reply index

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-06-18 11:40 Naruto Nguyen [this message]
2019-06-18 13:02 ` Steven Rostedt
2019-06-18 16:28   ` Naruto Nguyen

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