Messages in this thread | | | From | Andy Lutomirski <> | Date | Sat, 3 May 2014 16:51:37 -0700 | Subject | Re: [PATCH v2] x86: Return to kernel without IRET |
| |
On Sat, May 3, 2014 at 3:19 PM, H. Peter Anvin <hpa@zytor.com> wrote: > On 05/03/2014 04:24 AM, Steven Rostedt wrote: >> On Fri, 02 May 2014 21:03:10 -0700 >> "H. Peter Anvin" <hpa@zytor.com> wrote: >> >>> >>> I'd really like to see a workload which would genuinely benefit before >>> adding more complexity. Now... if we can determine that it doesn't harm >>> anything and would solve the NMI nesting problem cleaner than the >>> current solution, that would justify things, too... >>> >> >> As I stated before. It doesn't solve the NMI nesting problem. It only >> handles page faults. We would have to implement this for breakpoint >> return paths too. Is that a plan as well? >> > > I would assume we would do it for *ALL* the IRETs. There are only three > IRETs in the kernel last I checked...
I think we should carefully avoid doing it for returns from NMI, though :)
If you want a realistic benchmark that will speed up, packet forwarding might be a good place to look.
--Andy
| |