Re: LIO/sec per CPU limit? Is it Hardware or Oracle code?

From: Henry Poras <>
Date: Fri, 11 Aug 2017 14:52:45 -0400
Message-ID: <>


I agree about focusing on cpu (and perhaps memory). As for perf, from what I have seen it should be available. I'll check path, but I thought it might be a module not installed. I was able to start "perf stat" (didn't get a command not found) but then got some lib error. I'll go back and check.


On Fri, Aug 11, 2017 at 1:42 PM, Stefan Koehler <> wrote:

> Hello Henry,
> not quite sure what you are referring to as you are using Linux kernel
> 2.6.32-696.1.1.el6.x86_64 and perf is based on the perf_events interface
> and it is exported by Linux kernel >= 2.6.31 - maybe it is just not in your
> path ("/usr/sbin/perf").
> In addition i may got your description wrong but you wrote "A select
> count(*) from dba_objects showed this behavior as did Jonathan Lewis's
> kill_cpu script." - so you can completely ignore the I/O or network stack
> and focus on CPU (and memory) as kill_cpu (https://jonathanlewis.
> has nothing to do with these stacks.
> ... and if you want to analyze the CPU (and memory caching) behavior -
> measure it with perf and you will see the difference.
> Best Regards
> Stefan Koehler
> Independent Oracle performance consultant and researcher
> Website:
> Twitter: _at_OracleSK
> > Henry Poras <> hat am 11. August 2017 um 19:27
> geschrieben:
> >
> > Some more minor updates and responses to suggestions:
> >
> > Stefan - nice articles. Unfortunately neither turbostat or perf stat is
> available. I've asked the sysadms about this.

Received on Fri Aug 11 2017 - 20:52:45 CEST

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