[tor-bugs] #12891 [Tor]: Simulate KIST - global scheduling (#9262) and socket write limits (#12890)

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#12891: Simulate KIST - global scheduling (#9262) and socket write limits (#12890)
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     Reporter:  robgjansen  |      Owner:
         Type:  task        |     Status:  assigned
     Priority:  normal      |  Milestone:  Tor: 0.2.???
    Component:  Tor         |    Version:
   Resolution:              |   Keywords:  tor-relay, 027-triaged-1-out
Actual Points:              |  Parent ID:  #12541
       Points:              |
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Comment (by robgjansen):

 Update: using the model described in
 [https://trac.torproject.org/projects/tor/ticket/12890#comment:30 this
 comment], I ran KIST simulations using a variety of
 `KISTSockBufsizeFactor` settings (0.5, 1.5, 3.0) and compared the
 performance results against `UseKIST 0` (vanilla Tor). The results
 [https://trac.torproject.org/projects/tor/attachment/ticket/12891/kist.stablemodel.shadow
 .results-sm.pdf are attached here]. The high level result is that there
 was an insignificant change in performance among all settings tested.

 One possibility for the insignificant performance change is that the
 network is not congested enough for KIST to make a difference. To better
 understand this possibility, I'd like to run some cell tracking code that
 allows us to compute the Tor application and the shadow kernel buffer
 times. We can then compare buffer times, and see how those change as we
 add load to the network (e.g., by doubling the number of clients).

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12891#comment:12>
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