[GHC] #8982: Heap profile restricted by biography of GHC segfaults

[GHC]

#8982: Heap profile restricted by biography of GHC segfaults
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       Reporter:  ezyang          |             Owner:
           Type:  bug             |            Status:  new
       Priority:  normal          |         Milestone:
      Component:  Profiling       |           Version:  7.8.1
       Keywords:                  |  Operating System:  Linux
   Architecture:  x86_64 (amd64)  |   Type of failure:  Runtime crash
     Difficulty:  Unknown         |         Test Case:
     Blocked By:                  |          Blocking:
Related Tickets:                  |
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 Steps to reproduce:

 1. Build GHC with profiling on 64-bit Linux
 2. Run T1969 with RTS options -hc -hbvoid

 {{{
 [ezyang at hs01 compiler]$ '/home/hs01/ezyang/ghc-compalloc/inplace/bin/ghc-
 stage2' -fforce-recomp -dno-debug-output -no-user-package-db -rtsopts
 -fno-ghci-history -c T1969.hs   +RTS -V0 -tT1969.comp.stats --machine-
 readable -RTS -dcore-lint -static +RTS -hc -hbvoid
 Segmentation fault
 }}}

 Interestingly enough, I don't see the problem with other types of
 profiling, e.g. '-hd'. I tried a few simpler, nontrivial Haskell programs
 but I couldn't reproduce the segfault, so this is some sort of bug that
 only shows up in complex setting (maybe multithreading is the issue?) It
 reproduces quite reliably for me.

 When I build the runtime system with debugging, I get a useful assert
 failure:

 {{{
 ghc-stage2: internal error: ASSERTION FAILED: file rts/ProfHeap.c, line
 201

     (GHC version 7.8.0.20140408 for x86_64_unknown_linux)
     Please report this as a GHC bug:
 http://www.haskell.org/ghc/reportabug
 }}}

 This assert is complaining that the cost center (CCS_SYSTEM) never made it
 into the hash table for era 149.

 I'll try looking for a simpler test-case later, but maybe someone can
 figure out what this bug is by sight.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8982>
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