Re: machdep.cpu_idle_hlt and SMP perf?

From: M. Warner Losh <imp_at_bsdimp.com>
Date: Sat, 04 Feb 2006 08:59:17 -0700 (MST)
In message: <43E45BD8.7070708_at_fer.hr>
            Ivan Voras <ivoras_at_fer.hr> writes:
: Andrew Gallatin wrote:
: > Why dooes machdep.cpu_idle_hlt=1 drop my 10GbE network rx
: > performance by a considerable amount (7.5Gbs -> 5.5Gbs)?
: 
: For what it's worth, here are results of unixbench's "context1" 
: benchmark on an old P3 SMP with and without cpu_idle_hlt (6-stable):

When ACPI CPU states were coming into the tree, there was discussion
that they had been invented to provide a lower energy idle as well as
a faster transition from the idle state to something else.  I think
that these benchmarks show this effect rather dramatically.

Warner
Received on Sat Feb 04 2006 - 15:21:16 UTC

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