#6 simulator crashes with cache state error (george branch)

closed
6
2009-03-18
2008-12-13
No

I am running one of the bfs programs in the testsuite with the xmtsimulator-george branch of the simulator, which includes the shared DRAM actor.

The program crashes quite quickly with a cache error:

$ xmtsim -conf fpga1DRAM -cycle st15.sim -binload st15.b
Please contact the author of this software with
your source code and this error message:
Class: TwoPhaseRegisterArray.java Class version: 4967
Register L1_ACTOR_1.state already written: 4 (trying to write 2)
Cycle: 282
Stack trace:
java.lang.Thread.getStackTrace(Thread.java:1436)
xmtsim32.XMTSIMInternalError.<init>(XMTSIMInternalError.java:24)
xmtsim32.cycleaccurate.desim.TwoPhaseRegisterArray$TwoPhaseRegister.write(TwoPhaseRegisterArray.java:98)
xmtsim32.cycleaccurate.cache.L1Actor._serveL2Response(L1Actor.java:474)
xmtsim32.cycleaccurate.cache.L1Actor._phaseTwo(L1Actor.java:237)
xmtsim32.cycleaccurate.desim.BlockActor._notifyActor(BlockActor.java:61)
...

I traced it (both looking at cache activity and at packets track), and it doesn't seem to be because of a DRAM problem. It only happens when using the shared DRAM actor, but i think it's only because of the different timing.

What happens in the program: from the outlined_spawn_1, there are a lot of non-blocking stores issued to two arrays (level and tempH). Right after the spawn, there is a write from Master TCU to level[0]. Something happens at L1_ACTOR_1 and it becomes confused.

How to reproduce:
Download the george-devel version of the simulator from: https://subversion.umiacs.umd.edu/xmt/simulator/branches/devel/george/activity (revision 6218), compile simulator. Using this simulator, run with:

$ xmtsim -v
XMT Simulator
Simulator Version: 0.81.99george.r6218
Java Version: 1.6.0_11
$ xmtsim -conf fpga1DRAM -cycle st15.sim -binload st15.b
...

Discussion

  • George Caragea

    George Caragea - 2008-12-13

    test program that crashes (compiled and source code)

     
  • Fuat Keceli

    Fuat Keceli - 2009-01-13

    This bug is fixed in the keceli power branch. It will be committed to the development branch soon and will be made available with the next release.

     
  • Fuat Keceli

    Fuat Keceli - 2009-01-13
    • status: open --> pending
     
  • SourceForge Robot

    This Tracker item was closed automatically by the system. It was
    previously set to a Pending status, and the original submitter
    did not respond within 14 days (the time period specified by
    the administrator of this Tracker).

     
  • SourceForge Robot

    • status: pending --> closed
     

Log in to post a comment.