#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: new Priority: high | Milestone: Component: Profiling | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by jme): * owner: => jme Comment: The segfault occurs because `shrinkMutableByteArray#` and `resizeMutableByteArray#` introduce slop at the ends of the `large_object` `MutableByteArray#`s holding the `Integer`s. Since the arrays are large, they are not copied during GC, so this slop is still present when the heap census is run (after GC). But when `heapCensusChain` encounters a shrunken `MutableByteArray#`, it thinks the slop following the array is another closure, and chaos quickly ensues. The fix should be straightforward. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: new Priority: high | Milestone: Component: Profiling | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by jme): Thanks. Although I didn't verify it, I believe the culprit is the `show`, which repeatedly calls `quotRemInteger` to divide the result into smaller chunks. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:3 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: patch Priority: high | Milestone: Component: Profiling | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2005 Wiki Page: | -------------------------------------+------------------------------------- Changes (by jme): * status: new => patch * differential: => Phab:D2005 -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: merge Priority: high | Milestone: Component: Profiling | Version: 7.10.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2005 Wiki Page: | -------------------------------------+------------------------------------- Changes (by bgamari): * status: patch => merge -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: closed Priority: high | Milestone: 8.0.1 Component: Profiling | Version: 7.10.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2005 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"f0179e3adf6677243f587a05307a4a42833aa8d1/ghc" f0179e3/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="f0179e3adf6677243f587a05307a4a42833aa8d1" testsuite: Skip T11627a and T11627b on Darwin Darwin tends to give us a very small stack which the retainer profiler tends to overflow. Strangely, this manifested on CircleCI yet not Harbormaster. See #15287 and #11627. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:9 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#11627: Segmentation fault for space_leak_001 with profiling (-hc) -------------------------------------+------------------------------------- Reporter: thomie | Owner: jme Type: bug | Status: closed Priority: high | Milestone: 8.0.1 Component: Profiling | Version: 7.10.3 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: | perf/space_leaks/space_leak_001 Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Phab:D2005 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Ben Gamari ): In [changeset:"993782073c0b380908e9541c40c6c5849dbacfec/ghc" 9937820/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="993782073c0b380908e9541c40c6c5849dbacfec" testsuite: Fix a variety of issues when building with integer-simple * Mark arith011 as broken with integer-simple As noted in #16091, arith011 fails when run against integer-simple with a "divide by zero" exception. This suggests that integer-gmp and integer- simple are handling division by zero differently. * This also fixes broken_without_gmp; the lack of types made the previous failure silent, sadly. Improves situation of #16043. * Mark several tests implicitly depending upon integer-gmp as broken with integer-simple. These expect to see Core coming from integer-gmp, which breaks with integer-simple. * Increase runtime timeout multiplier of T11627a with integer-simple I previously saw that T11627a timed out in all profiling ways when run against integer-simple. I suspect this is due to integer-simple's rather verbose heap representation. Let's see whether increasing the runtime timeout helps. Fixes test for #11627. This is all in service of fixing #16043. }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11627#comment:11 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler