Why VHPT is disabled in the default configuration?

Linux-ia64 MAEDA Naoaki 2 participants 2 messages Aug 9, 2001

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MAEDA Naoaki

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2001-08-09 00:50 UTC #0 lore raw

Hi,

Dose anybody know why CONFIG_DISABLE_VHPT flag is set in the default kernel configuration?

I have tested the VHPT enabled kernel that shows better memory bandwidth and latency performance. If there are no concerns enabling the VHPT feature, it should be enabled in default, I think.

Regards,

Naoaki MAEDA

David Mosberger

2001-08-09 03:09 UTC #1 lore raw

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Quoted 1 line · MAEDA Naoaki

Naoaki> Hi, Dose anybody know why CONFIG_DISABLE_VHPT flag is set in Naoaki> the default kernel configuration?

Naoaki> I have tested the VHPT enabled kernel that shows better Naoaki> memory bandwidth and latency performance. If there are no Naoaki> concerns enabling the VHPT feature, it should be enabled in Naoaki> default, I think.

Yes, the VHPT should be enabled on recent CPUs (B3 or newer, IIRC). But you shouldn't assume that the default configuration included in the source code contains anything sensible.

	--david