Cost center heap profile restricted by biography of GHC segfaults

Steps to reproduce:

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

[ezyang@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.

Trac metadata

Trac field	Value
Version	7.8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Profiling
Test case
Differential revisions
BlockedBy
Related
Blocking
CC	simonmar
Operating system
Architecture

Edited Mar 09, 2019 by Edward Z. Yang

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