Messages in this thread | | | Subject | Re: [PATCH v2] x86: Return to kernel without IRET | From | "H. Peter Anvin" <> | Date | Sat, 03 May 2014 19:14:07 -0700 |
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Not for return from NMIs themselves, to be sure
On May 3, 2014 4:51:37 PM PDT, Andy Lutomirski <luto@amacapital.net> wrote: >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
-- Sent from my mobile phone. Please pardon brevity and lack of formatting.
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