1. 26 Apr, 2004 1 commit
    • Robert Ricci's avatar
      Some big changes to assign, and some related changes to assign_wrapper · 238dce73
      Robert Ricci authored
      and ptopgen.
      
      Add link typing to assign. Each virtual link is given a single type.
      Each physical link is given one or more types. A virtual link will
      only be mapped to a physical link which can satisfy its type. In both
      the top and ptop files, the link types are now mandatory, and they
      fall at the end of the mandatory link arguments.
      
      This differers from the 'regular' type system in two ways. First, a
      plink is not constrained to filling only one type at a time. If we are
      using emulated links, a plink could satisfy, say, an 'ethernet' link
      and an 'fxp' link at the same time. This seems to more naturally match
      the way we'll use link types.  Second, there are no counts assoicated
      with link types, as there are for node types. ie. a link is not an
      'ethernet:1' link, it's an 'ethernet' link. Presumably, when
      multiplexing virtual links onto a physical one, it's bandwidth that's
      the factor that limits the multiplexing.
      
      The link type is now taken into account when constructing pclasses,
      and in the mapping precheck.
      
      As a side-effect of these changes, the silly 'count' argument on the
      end of link lines in the ptop file, which was used for the fake LAN
      nodes, is no longer supported.
      
      The implementation could be a bit more efficient, but that would mean
      tossing more of the stuff we do with boost's graph library. I think
      this should happen, but today is not the day.
      
      Modify assign_wrapper and ptopgen to spit out top and ptop files in
      the new format.
      
      Changed the constant LINK_UKNOWN to LINK_UNMAPPED - the new name more
      accurately reflects the way this constant is used.
      
      Add a new '-n' flag that tells assign not to do annealing, just exit
      after the type precheck.
      
      Clarify the usage message for the -c flag.
      
      Removed some dead code for dealing with LAN nodes.
      238dce73
  2. 07 Jan, 2004 1 commit
    • Robert Ricci's avatar
      Fix dynamic pclasses, and make them the default for virtual nodes · c7e2d29e
      Robert Ricci authored
      again.
      
      One of the fixes changes the way in which we iterate through pclasses
      in find_pnode(). We used to treat the vector like a ring buffer, and
      start (randomly) someplace in the middle. This turns out to give some
      bad statistical properties when doing dynamic pclasses, since long
      chains of disabled pclasses will cause some pclasses to be selected
      more often. My old hack of just hopping around randomly in the
      disabled-pclass case was bad, because it's hard to tell when you've
      actually tried all the pclasses - so, we were getting false negatives
      where it was looking like there was no place available where we could
      map a vnode, which turned out to have worse effects than I had
      thought.
      
      So, now, we make a list of all the indices and randomize the order,
      then just iterate through that list.
      
      We also now count the number of pclasses that are enabled at every
      temperature step, and adjust the neighborhood size to remove them.
      This makes dynamic pclasses quite a bit faster - it cuts the time
      by 30% - 50% for my test case.
      
      Cleaned up find_pnode() by removing some #ifdef's that we don't use,
      and probably will never want to again - this makes the function almost
      readable!
      c7e2d29e
  3. 05 Dec, 2003 1 commit
  4. 11 Sep, 2003 1 commit
  5. 10 Sep, 2003 1 commit
  6. 09 Sep, 2003 1 commit
  7. 04 Sep, 2003 1 commit
  8. 21 Aug, 2003 1 commit
    • Robert Ricci's avatar
      Okay, add back some of my static nodes/multiplexing changes, · da47400b
      Robert Ricci authored
      really working this time.
      
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      I will not check things in without running the testsuite
      da47400b
  9. 08 Aug, 2003 1 commit
  10. 07 Aug, 2003 1 commit
    • Robert Ricci's avatar
      A lot of bugfixes relating, primarily, to multiplexed nodes: · 821107fc
      Robert Ricci authored
      Split the function that determines if a vnode can be mapped to a given pnode
      out of find_pnode, so that I can spread it out and make it more comprehensible.
      In doing so, fixed a bug in which static types were not getting handled
      correctly - a static type would only be found if no vnodes with dynamic types
      were allocated to the pnode.
      
      Fixed a bug in which, on allocation of a dynamic ptype, nodes where being
      removed from their static type lists in the type_table.
      
      Fixed a bug when there is a combination of fixed and un-fixed vnodes in the top
      file.
      
      I have more on the way, but this seemed like a good checkpoint.
      821107fc
  11. 10 Jul, 2003 1 commit
    • Robert Ricci's avatar
      Fix a major bug in dynamic pclasses. One of thse little things that · bc6c6a54
      Robert Ricci authored
      was sooo wrong you wonder how it worked in the first place... Took
      me days to find this one!
      
      Also added a new switch, '-o', that lets assign try out solutions
      that over-load a pnode. This helps a lot with topologies where the
      optimal solution is a best-fit onto multiplexed pnodes.
      
      The end result is that Mike's snake maps much better - it used to get
      an essentially random mapping, but now it gets something acceptible.
      bc6c6a54
  12. 01 Jul, 2003 1 commit
    • Robert Ricci's avatar
      Give assign the ability to make dynamic pclasses. Here's how it works: · fbcd6752
      Robert Ricci authored
      After building the set of pclasses normally, we make another pass
      through the vnodes. The goal to create a pclass for each individual
      node. We disable the node's 'own' pclass to begin with. Then, the
      _first_ time it gets a vnode mapped to it, we remove it from the
      'regular' pclass it belongs to, and enable it's own pclass. Then, if
      it goes empty, we put it back in its regular pclass and disable it's
      own.
      
      The point of this is to replace -p for use with multiplexed nodes.
      Instead of disabling pclasses altogheter, which has serious
      performance implications, we can instead be smart about which pnodes
      remain equivalent (because nothing's been mapped to them), and which
      are now different. The result is that on my test topoloy, the time to
      get a good mapping has gone from over 3 minutes to about 6 seconds.
      
      This feature is enabled with the -d option, and the -P option is
      pretty much mandatory when using it, since it greatly exacerbates the
      problem of cruft in the ptop file.
      
      This satisfies #14 from the todo file:
      14.  do dynamic pclasses
      
      Also bumped up the minimum neighborhood size from 500 to 1000. In some
      tests I was doing, this resulted in better solutions.
      fbcd6752
  13. 26 Jun, 2003 1 commit
    • Robert Ricci's avatar
      Major changes to the way assign handles LAN nodes. · 83cfa8ec
      Robert Ricci authored
      LAN nodes are no longer treated specially. Instead, I've introduced
      the idea of 'static' types (old-style types retroactively become
      'dynamic' types). While a pnode can only satisfy one dynamic type at a
      time, it can always satisfy its static types (assuming it has enough
      capacity left.) Static types are flagged by prepending them with a '*'
      in the ptop file. So, for example, you may give switches the
      '*lan:10000' type so that they can satisfy virtual LAN nodes. Of
      course, other pnodes can have this type too, so that we can get
      'trivial LANs'.
      
      Actually, removing special treatment for LANs cleans up a lot of code.
      However, it may have some negative impacts on solutions, since we're
      not as smart about where to place LAN nodes as we used to be (they get
      annealed along with everything else, and not migrated.) I haven't seen
      any evidence of this yet, however.
      
      This leaves us with a single type of special pnode, a switch.
      
      Also added a new bit of syntax in ptop files - when '*' is given as a
      the maxiumum load for a type, the node is allowed to take on an
      infinite (well, actually, just a really big number of) vnodes of that
      type.
      
      ptopgen was modified to always report switches as being capable of
      hosting LANs, and assign_wrapper now understands direct links to LANs,
      which is what we get when the LAN is hosted directly on a switch.
      
      Fixed a bug in scoring direct links, in which the penatly was being
      added once when a direct link was mapped, but subtracted only once
      when it was freed.
      
      Added a '-T' option for doing simple self-testing. When adding a node
      to the solution, assign records the score, adds the node, removes it
      again, and checks to make sure that the resulting score is the same as
      the original score. The usefulness of this feature in debugging
      scoring problems cannot be understated...
      83cfa8ec
  14. 20 Jun, 2003 1 commit
  15. 11 Mar, 2003 1 commit
  16. 05 Mar, 2003 1 commit
  17. 10 Feb, 2003 1 commit
  18. 05 Feb, 2003 2 commits
  19. 03 Jul, 2002 1 commit
  20. 08 Jan, 2002 1 commit
    • Christopher Alfeld's avatar
      All the vclass stuff. Can now do: · 09737efc
      Christopher Alfeld authored
      make-vclass A 0.5 pc600 pc850
      
      in the top file.  And then have nodes of type A.  Assign will try to put
      them all as either pc600 or pc850.
      
      Still need to write all the pre-assign stuff.
      09737efc
  21. 07 Jan, 2002 1 commit
  22. 02 Jan, 2002 1 commit
    • Christopher Alfeld's avatar
      · 1eb1e1d9
      Christopher Alfeld authored
      This check-in consists of 7 modifications to assign.
      
      1. Equivalence Classes
      
      Defined an equivalence relation on the physical nodes and applied it
      to the physical topology to get the resulting quotient topology (abuse
      of terminology).  So instead of searching among all possible physical
      nodes to make a map, assign only searches among all possible
      equivalence classes of nodes.  This tremendously reduces the search
      space.  At the time of this writing it reduces the physical topology
      from 252 nodes to 13 nodes.  The equivalence classes are generated
      automatically from the ptop file.
      
      2. Scoring based on equivalence classes.
      
      Each equivalence class used comes with a significant cost.  This
      strongly encourages assign to use equivalence machines when possible.
      The result is that an experiment that does not otherwise specify will
      almost definitely get machines of the same type.  If this needs to be
      reduced in the future it is the SCORE_PCLASS constant.
      
      3. Heuristics
      
      Added a bunch of heuristics for choosing which equivalence class to
      use.  This was less successful than I hoped.  A good solution is now
      found in record time but it still continues searching.  When OPTIMAL
      is turned on these heuristics help a lot.  When off they make little
      difference.  I may turn this into a compile time option in the future
      since the heuristics do take non-trivial CPU cycles.
      
      4. Fixed the very-very-big-and-evil disconnected-switches bug.
      
      Assign wasn't cleaning up after itself in certain cases.  Disconnected
      graphs are now merely a minor, easily ignored, bump rather than the
      towering cliffs they use to be.
      
      5. Fixed the not-yet-noticed not-enough-nodes bug.
      
      Found a bug that probably has never come up before because we have
      checks that avoid those circumstances.
      
      6. Modified constants.
      
      I was tired of waiting so long for results so, I lowered CYCLES and
      reduced the constant for naccepts (Mac, you probably want to add that
      inconspicuous number to your configurable constants; look for
      "naccepts =").  The results is roughly a speedup of 2.  It works great
      currently but we may want to change these numbers up again if we get
      problems with features and desires.
      
      7. General clean up.
      
      Associated with the other changes was a lot of restructuring and some
      cleanup.  Specifically to the assign loop and scoring code.
      1eb1e1d9