[tor-bugs] #12170 [Tor]: Investigate performance issues surrounding count_usable_descriptors()

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#12170: Investigate performance issues surrounding count_usable_descriptors()
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     Reporter:  nickm   |      Owner:
         Type:  defect  |     Status:  needs_review
     Priority:  normal  |  Milestone:  Tor: 0.2.5.x-final
    Component:  Tor     |    Version:
   Resolution:          |   Keywords:  024-backport tor-relay performance
Actual Points:          |  Parent ID:  #11332
       Points:          |
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Comment (by arma):

 Re your patch, I think the change is fine. Two questions:

 First:
 {{{
 +    if (bool_neq(node->is_running, up))
 +      router_dir_info_changed();
 +
      node->is_running = up;
 }}}
 Why not put the assignment inside the if also, since we know it won't
 happen otherwise and it's clearer to say it? Or is it clearer to show that
 no matter what, afterwards the value of is_running will be the same as the
 value of up? This is a style question.

 Second: in your commit message, "This patch makes us call it only when we
 have a router that we previously believed to be down, and we found it to
 be up." -- note that router_set_status() can be called with "up" false,
 meaning it's down, and I think your patch affects that side of the
 situation too (and it should).

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/12170#comment:4>
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