Re: [benchmark] 1% performance overhead of paravirt_ops on nativekernels

From: Linus Torvalds
Date: Tue Jun 09 2009 - 14:07:26 EST




On Tue, 9 Jun 2009, H. Peter Anvin wrote:
>
> A major problem is that distros don't seem to be willing to push 64-bit
> kernels for 32-bit distros. There are a number of good (and
> not-so-good) reasons why users may want to run a 32-bit userspace, but
> not running a 64-bit kernel on capable hardware is just problematic.

Yeah, that's just stupid. A 64-bit kernel should work well with 32-bit
tools, and while we've occasionally had compat issues (the intel gfx
people used to claim that they needed to work with a 32-bit kernel because
they cared about 32-bit tools), they aren't unfixable or even all _that_
common.

And they'd be even less common if the whole "64-bit kernel even if you do
a 32-bit distro" was more common.

The nice thing about a 64-bit kernel is that you should be able to build
one even if you don't in general have all the 64-bit libraries. So you
don't need a full 64-bit development environment, you just need a compiler
that can generate code for both (and that should be the default on x86
these days).

Linus
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