Re: Threaded execution (was: Interesting Bugs in 12cR1)

From: Frits Hoogland <frits.hoogland_at_gmail.com>
Date: Fri, 12 Jul 2013 20:33:59 +0200
Message-Id: <3EF359A8-09DA-4196-84A9-E1359320C3DF_at_gmail.com>

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On a VM, it's needed to use an alternative for native cpu timing (-e = cpu-clock), but you've done that, otherwise you would see nothing.

What is your kernel version? A quick peek on the internet shows it seems = to be a clock-source problem with older kernel versions. I haven't seen = this with 2.6.32+

Frits Hoogland

http://fritshoogland.wordpress.com
frits.hoogland_at_gmail.com
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On Jul 12, 2013, at 8:08 PM, Niall Litchfield = <niall.litchfield_at_gmail.com> wrote:

>=20

> On Jul 12, 2013 6:28 PM, "Frits Hoogland" <frits.hoogland_at_gmail.com> = wrote:

> >
> > It depends on where the time is spend. Use perf top or record to
> > measure functions for threaded and non threaded performance.

>=20

> I'm so glad you said that :). Consistently when I do this (on a vm) = the greatest single sample count is for acpi_pm_read. There's no good = explanation I've found for this. I have some ideas but 30% of samples in = this call compared with <5% in the various qer* Oracle function calls = seems wrong in a swingbench test. I suspect I'm missing the idiots guide = to perf/linux kernel functions..
>=20

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Received on Fri Jul 12 2013 - 20:33:59 CEST