Re: [PATCH v2 08/10] x86-64: Emulate vsyscalls

Ingo Molnar
2011-05-30T08:07:33Z

* Jan Beulich <JBeulich@novell.com> wrote:

> >>> On 30.05.11 at 05:48, Andy Lutomirski <luto@MIT.EDU> wrote:
> > This causes vsyscalls to be a little more expensive than real
> > syscalls. Fortunately sensible programs don't use them.
>
> Hmm - weren't vsyscalls there for performance reasons?

New code uses the vDSO. The fixed-address vsyscalls are apparently
only used in esoteric cases like statically linked glibc binaries.
(which should arguably be using the vDSO as well)

Thanks,

Ingo