Messages in this thread | | | Subject | Re: [PATCH RFC/RFB] x86_64, i386: interrupt dispatch changes | From | Matt Mackall <> | Date | Thu, 13 Nov 2008 16:23:59 -0600 |
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On Mon, 2008-11-10 at 21:00 -0800, H. Peter Anvin wrote: > Okay, after spending most of the day trying to get something that isn't > completely like white noise (interesting problem, otherwise I'd have > given up long ago) I did, eventually, come up with something that looks > like it's significant. I did a set of multiple runs, and am looking for > the "waterfall points" in the cumulative statistics. > > http://www.zytor.com/~hpa/baseline-hpa-3000-3600.pdf > > This particular set of data points was gathered on a 64-bit kernel, so I > didn't try the segment technique. > > It looks to me that the collection of red lines is enough to the left of > the black ones that one can assume there is a significant effect, > probably by about a cache miss worth of time.
This graph is a little confusing. Is the area under each curve here supposed to be a constant?
Is this latency from all interrupts as seen by userspace? Or does a particular interrupt dominate?
-- Mathematics is the supreme nostalgia of our time.
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