Messages in this thread | | | From | Rusty Russell <> | Subject | Re: [Lguest] [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes | Date | Mon, 1 Dec 2008 15:02:35 +1030 |
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On Sunday 30 November 2008 04:52:41 Avi Kivity wrote: > Alexander van Heukelum wrote: > > I now did the benchmarks for the same -rc6 with hpa's 4-byte stubs > > too. Same machine. It's significantly better than the other two > > options in terms of speed. It takes about 7% less cpu to handle > > the interrupts. (0.64% cpu instead of 0.69%.) I have to run now, > > I'll let interpreting the histogram to someone else ;). > > This is noise. 0.05% cpu on a 1GHz machine servicing 1000 interrupt/sec > boils down to 500 cycles/interrupt. These changes shouldn't amount to > so much (and I doubt you have 1000 interrupts/sec with a single disk)..
Sure, but smallest cache wins. Which is why I thought hpa chose the 3 byte option.
> I'm sorry, but the whole effort is misguided, in my opinion.
Respectfully disagree. I wouldn't do it, but it warms my heart that others are. It's are not subtractive from other optimization efforts.
Cheers, Rusty.
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