From: Michael Breuer <mbreuer@majjas.com>
To: linux-kernel@vger.kernel.org
Subject: Problem? intel_iommu=off; perf top shows acpi_os_read_port as extremely busy
Date: Fri, 27 Nov 2009 19:20:16 -0500 [thread overview]
Message-ID: <4B106CC0.4050406@majjas.com> (raw)
Having given up for now on VT-D, I rebooted 2.6.38 rc8 with
intel_iommu=off. Whilst my myriad of broken bios issues cleared, I now
see in perf top acpi_os_read_port as continually the busiest function.
With intel_iommu enabled, _spin_lock was always on top, and nothing else
was notable.
This seems odd to me, perhaps this will make sense to someone else.
FWIW, I'm running on an Asus p6t deluxe v2; ht enabled; no errors or
oddities in dmesg or /var/log/messages.
next reply other threads:[~2009-11-28 0:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-11-28 0:20 Michael Breuer [this message]
2009-11-28 7:18 ` Problem? intel_iommu=off; perf top shows acpi_os_read_port as extremely busy Ingo Molnar
2009-11-28 15:27 ` Peter Zijlstra
2009-11-28 15:47 ` Michael Breuer
2009-11-28 17:45 ` Arjan van de Ven
2009-11-28 18:10 ` Michael Breuer
2009-11-29 20:47 ` Arjan van de Ven
2009-11-30 5:11 ` Michael Breuer
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