Re: [RFC PATCH v2 6/6] x86/entry/pti: don't switch PGD on when pti_disable is set

[Alan Cox]

On Thu, 11 Jan 2018 13:26:01 -0600
Josh Poimboeuf <jpoimboe@xxxxxxxxxx> wrote:

> On Thu, Jan 11, 2018 at 08:19:35PM +0100, Olivier Galibert wrote:
> > Wouldn't the time taken by an easy syscall like getuid be a clear indicator?  
> 
> I think only if you had a baseline measurement to compare against.

getuid can also be cached by a smart libc. getppid() is what micro
benchmarks seem to favour.

Alan