Messages in this thread | | | Date | Wed, 22 Jun 2005 11:50:19 -0700 | From | "Paul E. McKenney" <> | Subject | Re: PREEMPT_RT vs I-PIPE: the numbers, part 2 |
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On Wed, Jun 22, 2005 at 01:20:03PM -0400, Kristian Benoit wrote: > On Wed, 2005-06-22 at 09:27 -0700, Paul E. McKenney wrote: > > On Wed, Jun 22, 2005 at 11:31:39AM -0400, Karim Yaghmour wrote: > > > > If I understand your analysis correctly (hah!!!), your breakdown > > of the maximum delay assumes that the maximum delays for the logger > > and the target are correlated. What causes this correlation? > > My (probably hopelessly naive) assumption would be that there would > > be no such correlation. In absence of correlation, one might > > approximate the maximum ipipe delay by subtracting the -average- > > ipipe delay from the maximum preemption delay, for 55us - 7us = 48us. > > Is this the case, or am I missing something here? > > Your analysis is correct, but with 600,000 samples, it is possible that > we got 2 peeks (perhaps not maximum), one on the logger and one on the > target. So in my point of view, the maximum value is probably somewhere > between 55us / 2 and 55us - 7us. And probably closer to 55us / 2.
Possible, but it could also be a large peak and a small one.
Any way of getting the logger's latency separately? Or the target's?
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