Re: [patch] paravirt: VDSO page is essential

From: Avi Kivity
Date: Mon Mar 05 2007 - 09:13:11 EST


Ingo Molnar wrote:
* Andi Kleen <ak@xxxxxxx> wrote:

I think we would need to have a paravirt ops callback to decide this first. But it doesn't look critical to me anyways.

well, it's critical to me in two ways: 1) to make the i386 paravirt code clean 2) to have a proper VDSO for a KVM paravirtual guest. The original change is also bad because it changes how a Linux guest behaves: it turns off the vdso by default, and disables the compat VDSO. I.e. it's a bad performance step backwards if CONFIG_PARAVIRT is enabled (uses int $0x80 instead of sysenter), which hurts only KVM and basically none of the other hypervisors. It also muddifies the VDSO picture wrt. virtualization.


kvm paravirt is only used by developers at this time. I don't have a problem with solving this in the 2.6.22 timeframe.

--
error compiling committee.c: too many arguments to function

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