Re: [PATCH 03/16] x86/entry/32: Leave the kernel via the trampoline stack

From: Joerg Roedel
Date: Fri Jan 19 2018 - 04:57:16 EST


On Wed, Jan 17, 2018 at 10:12:32AM -0800, Andy Lutomirski wrote:
> I would optimize for simplicity, not speed. You're already planning
> to write to CR3, which is serializing, blows away the TLB, *and* takes
> the absurdly large amount of time that the microcode needs to blow
> away the TLB.

Okay, so I am going to do the stack-switch before pt_regs is restored.
This is at least better than playing games with hiding the entry/exit
%esp somewhere in stack-memory.


Thanks,

Joerg