#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted -------------------------------------+------------------------------------- Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Changes (by thomie): * Attachment "InstanceSerialize.hs" added. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted -------------------------------------+------------------------------------- Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Operating System: Linux | Architecture: Type of failure: Compile-time | Unknown/Multiple crash | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Revisions: -------------------------------------+------------------------------------- Changes (by thomie): * related: => #5642, #9675 Comment: I can't reproduce that panic on x86-64 Linux with ghc-7.10.2, but do notice GHC needs an awful lot of memory to compile `chatter`. My laptop starts swapping. I extracted an example. Run `cabal install cereal-0.4.1.0` first (`cereal` doesn't have dependencies itself, and doesn't take long to build). {{{ $ ghc-7.10.2 -fforce-recomp InstanceSerialize.hs -dshow-passes -O +RTS -s 105,749,837,048 bytes allocated in the heap 34,168,091,184 bytes copied during GC 1,094,766,416 bytes maximum residency (31 sample(s)) 13,390,536 bytes maximum slop 2797 MB total memory in use (0 MB lost due to fragmentation) Tot time (elapsed) Avg pause Max pause Gen 0 2770 colls, 0 par 109.295s 117.115s 0.0423s 2.0924s Gen 1 31 colls, 0 par 124.908s 198.248s 6.3951s 25.1279s TASKS: 4 (1 bound, 3 peak workers (3 total), using -N1) SPARKS: 0 (0 converted, 0 overflowed, 0 dud, 0 GC'd, 0 fizzled) INIT time 0.001s ( 0.001s elapsed) MUT time 284.506s (326.497s elapsed) GC time 234.203s (315.363s elapsed) EXIT time 0.001s ( 0.001s elapsed) Total time 518.747s (641.862s elapsed) Alloc rate 371,696,208 bytes per MUT second Productivity 54.9% of total user, 44.3% of total elapsed gc_alloc_block_sync: 0 whitehole_spin: 0 gen[0].sync: 0 gen[1].sync: 0 }}} The full log is attached. I notice the number of terms increases by a factor of 8 after the first simplifier pass. I don't know if that is normal. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted ---------------------------------------+--------------------------------- Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: arm Operating System: Linux | Architecture: arm Type of failure: Compile-time crash | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Revisions: ---------------------------------------+--------------------------------- Changes (by thomie): * architecture: Unknown/Multiple => arm -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted ---------------------------------------+------------------------------ Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: arm Operating System: Linux | Architecture: arm Type of failure: Compile-time crash | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Rev(s): Wiki Page: | ---------------------------------------+------------------------------ Comment (by andrewufrank): a simpler example - pureMD5 does give the same result (again on an armhf with ghc 7.10.2.20151030 {{{ Glasgow Haskell Compiler, Version 7.10.2.20151030, stage 2 booted by GHC version 7.10.2.20151030 Using binary package database: /usr/lib/ghc/package.conf.d/package.cache Using binary package database: /home/frank/.ghc/arm- linux-7.10.2.20151030/package.conf.d/package.cache wired-in package ghc-prim mapped to ghc- prim-0.4.0.0-087c70fa92d0fbd8056dbc5853433ed1 wired-in package integer-gmp mapped to integer- gmp-1.0.0.0-c6adc6639382c14317a5926d860e24d8 wired-in package base mapped to base-4.8.2.0-6d4788b4fac4bef0277f64a0a9ece0ab wired-in package rts mapped to builtin_rts wired-in package template-haskell mapped to template- haskell-2.10.0.0-96406e1c046e7d3794950273552e30d5 wired-in package ghc mapped to ghc-7.10.2.20151030-28f5d1fe7d4210612a8dc6732b57dced wired-in package dph-seq not found. wired-in package dph-par not found. Hsc static flags: *** Deleting temp files: Deleting: *** Deleting temp dirs: Deleting: ghc: no input files }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted ---------------------------------------+------------------------------ Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: arm Operating System: Linux | Architecture: arm Type of failure: Compile-time crash | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Rev(s): Wiki Page: | ---------------------------------------+------------------------------ Description changed by bgamari: Old description:

i tried to compile (cabal install) chatter-0.5.2.0 on a armbian (debian jessie, with ghc 7.10.2-1 from testing, running on a cubietruck ARMHF Cortex A20) and get in file NLP.Corpora.Conll a panic:

[ 9 of 23] Compiling NLP.Corpora.Conll ( src/NLP/Corpora/Conll.hs, dist/build/NLP/Corpora/Conll.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for arm-unknown-linux): Simplifier ticks exhausted When trying UnfoldingDone $fGSerialize:*:_$s<$> To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 2748218

i do not notice anything particular in the code, except a very long data type with enumerated values. I tried with a higher value for tick-factor (1000) with no improvement.

i will now try to run 7.10.2-2 from experimental.

New description: i tried to compile (cabal install) chatter-0.5.2.0 on a armbian (debian jessie, with ghc 7.10.2-1 from testing, running on a cubietruck ARMHF Cortex A20) and get in file `NLP.Corpora.Conll` a panic: {{{ [ 9 of 23] Compiling NLP.Corpora.Conll ( src/NLP/Corpora/Conll.hs, dist/build/NLP/Corpora/Conll.o ) ghc: panic! (the 'impossible' happened) (GHC version 7.10.2 for arm-unknown-linux): Simplifier ticks exhausted When trying UnfoldingDone $fGSerialize:*:_$s<$> To increase the limit, use -fsimpl-tick-factor=N (default 100) If you need to do this, let GHC HQ know, and what factor you needed To see detailed counts use -ddump-simpl-stats Total ticks: 2748218 }}} i do not notice anything particular in the code, except a very long data type with enumerated values. I tried with a higher value for tick-factor (1000) with no improvement. i will now try to run 7.10.2-2 from experimental. -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted ---------------------------------------+------------------------------ Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: arm Operating System: Linux | Architecture: arm Type of failure: Compile-time crash | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Rev(s): Wiki Page: | ---------------------------------------+------------------------------ Comment (by bgamari): While I have no problem compiling `Conll`, the `Brown` module is indeed quite problematic, even on my laptop. This module produces an absolutely absurd amount of Core which appears to originate from the generic `Serialize` instances for the quite large `Tag` type. The attached `Test.hs` reproduces the blow-up. While the code size starts large-but-not insane, {{{ Result size of Desugar (after optimization) = {terms: 25,522, types: 972,788, coercions: 376,020} }}} Things quickly balloon during float-out, {{{ *** Float out(FOS {Lam = Just 0, Consts = True, OverSatApps = False}): Result size of Float out(FOS {Lam = Just 0, Consts = True, OverSatApps = False}) = {terms: 254,872, types: 3,162,281, coercions: 634,615} }}} which the simplifier, through a great deal of effort, manages to reduce down to, {{{ Result size of CorePrep = {terms: 49,840, types: 1,752,631, coercions: 442,468} }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted -------------------------------------+------------------------------------- Reporter: andrewufrank | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 7.10.2 Resolution: | Keywords: Generics Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by bgamari): rwbarton, the testcase is already attached (attachment:InstanceSerialize.hs). Your assessment sounds about right. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler

#10852: ghc 7.8.4 on arm - panic: Simplifier ticks exhausted -------------------------------------+------------------------------------- Reporter: andrewufrank | Owner: Type: bug | Status: closed Priority: high | Milestone: Component: Compiler | Version: 7.10.2 Resolution: duplicate | Keywords: Generics Operating System: Unknown/Multiple | Architecture: Type of failure: Compile-time | Unknown/Multiple performance bug | Test Case: Blocked By: | Blocking: Related Tickets: #5642, #9675 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Changes (by thomie): * status: new => closed * resolution: => duplicate Comment: Moving to #12148, since this issue is not ARM specific, and this ticket is getting confusing. I'll copy the relevant parts from the comments above. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10852#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler