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Re: performance differences: "maxcpus=1" vs. "echo 0 > /sys/devices/system/cpu/cpu1/online"

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To: Luciano Rocha <luciano@...>
Cc: Michael Meyer <mike65134@...>, <linux-kernel@...>
Date: Tuesday, March 25, 2008 - 1:16 pm

Luciano Rocha <luciano@eurotux.com> writes:


CPU hot unplug will do the same. But it is unlikely it accounts
for that much performance difference.

If he used maxcpus=0 it would make sense. maxcpus=0 disables
the IO-APIC which likely makes a large difference. But it should
be actually slower.

There should be actually no difference in theory between max_cpus=1
and hot unplug to one CPU. Might be some bug.

-Andi
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Messages in current thread:
Re: performance differences: "maxcpus=1" vs. "echo 0 > /s..., Andi Kleen, (Tue Mar 25, 1:16 pm)
Re: performance differences: "maxcpus=1" vs. "echo 0 &gt; /s..., Wander Winkelhorst, (Tue Mar 25, 1:49 pm)
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