[tor-bugs] #24665 [Core Tor/Tor]: sched: In KIST, the extra_space kernel value needs to be allowed to be negative

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#24665: sched: In KIST, the extra_space kernel value needs to be allowed to be
negative
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 Reporter:  dgoulet       |          Owner:  dgoulet
     Type:  defect        |         Status:  needs_review
 Priority:  Very High     |      Milestone:  Tor: 0.3.2.x-final
Component:  Core Tor/Tor  |        Version:  Tor: 0.3.2.1-alpha
 Severity:  Normal        |     Resolution:
 Keywords:  tor-sched     |  Actual Points:
Parent ID:                |         Points:
 Reviewer:                |        Sponsor:
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Comment (by yawning):

 The branch looks sensible to me.

 My inner pedant will say that "If a connection to a relay was unreliable
 meaning tor was struggling to flush bytes towards the relay" is misleading
 at best, since the congestion window shrinking (by quite a bit) is an
 expected part of how TCP/IP works and not particularly indicative of an
 overloaded condition on it's own.

 While you're here, assuming the scheduler is called significantly faster
 than the RTT of most links (read that as "If 10 ms is lower than the RTT
 of most if not all links"), you can/should reduce `sock_buf_size_factor`
 as well, because you aren't going to get a full congestion window worth of
 ACKs back between scheduler calls in common cases.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/24665#comment:2>
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