#12009: ASSERTION FAILED: file rts/LdvProfile.c, line 48 -------------------------------------+------------------------------------- Reporter: erikd | Owner: erikd Type: bug | Status: new Priority: normal | Milestone: 8.0.2 Component: Compiler | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by erikd): Wow, this is interesting. Note that I am running the test program with `+RTS -hb -DS -N1` and its crashing in `processNurseryForDead` which has some code that looks like: {{{ p = bd->start; while (p < bd->free) { while (p < bd->free && !*p) p++; // skip slop if (p >= bd->free) break; }}} The line with the `skip slop` comment is the interesting one. It assumes that if the block descriptor we are currently looking at is not full, then the memory from `bd->start` to `bd-free` with be all zeros. However, this is not the case when the RTS flags include `-DS` which turns on sanity checking. One part of this sanity checking is in the function `resetNurseries` of the file `rts/sm/Storage.c` which does this: {{{ IF_DEBUG(sanity, memset(bd->start, 0xaa, BLOCK_SIZE)); }}} That is, it fills the block with `0xaa` bytes which causes the "skip slop" code in `processNurseryForDead` to incorrectly skip the slop at the start of the block. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/12009#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler