Messages in this thread | | | Date | Sat, 29 Nov 2008 20:21:22 +0200 | From | Avi Kivity <> | Subject | Re: [Lguest] [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes |
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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)..
I'm sorry, but the whole effort is misguided, in my opinion. If you want to optimize, try reducing the number of interrupts that occur rather than saving a few cycles in the interrupt path.
-- I have a truly marvellous patch that fixes the bug which this signature is too narrow to contain.
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