#4856: Performance regression in the type checker regression for GADTs and type
families
-------------------------------------------+--------------------------------
Reporter: chak | Owner:
Type: bug | Status: closed
Priority: normal | Milestone: 7.2.1
Component: Compiler (Type checker) | Version: 7.0.1
Resolution: fixed | Keywords:
Testcase: | Blockedby:
Difficulty: | Os: Unknown/Multiple
Blocking: | Architecture: Unknown/Multiple
Failure: Compile-time performance bug |
-------------------------------------------+--------------------------------
Changes (by simonpj):
* status: new => closed
* resolution: => fixed
Comment:
OK, I ran a complete build of the `accelerate` library thus:
{{{
runhaskell Setup.hs clean
runhaskell Setup.hs configure --with-ghc=/home/simonpj/builds/validate-
HEAD/inplace/bin/ghc-stage2
time runhaskell Setup.hs build
}}}
I added `+RTS -s -RTS` to the opts in `accelerate.cabal`. Headline
results:
* GHC 6.12.3: 45 sec
* GHC 7.0.3: 40 sec
* '''GHC 7.2: 35 sec'''
Result, happiness. Details:
{{{
===================== GHC 6.12.3 ============================
14,320,835,376 bytes allocated in the heap
4,597,762,168 bytes copied during GC
229,976,136 bytes maximum residency (27 sample(s))
10,919,512 bytes maximum slop
662 MB total memory in use (11 MB lost due to fragmentation)
Generation 0: 27057 collections, 0 parallel, 9.89s, 9.95s elapsed
Generation 1: 27 collections, 0 parallel, 5.90s, 6.33s elapsed
Parallel GC work balance: -nan (0 / 0, ideal 1)
MUT time (elapsed) GC time (elapsed)
Task 0 (worker) : 0.00s ( 27.49s) 0.00s ( 0.00s)
Task 1 (worker) : 0.00s ( 27.54s) 0.00s ( 0.00s)
Task 2 (bound) : 26.04s ( 27.54s) 15.79s ( 16.28s)
SPARKS: 0 (0 converted, 0 pruned)
INIT time 0.01s ( 0.00s elapsed)
MUT time 25.45s ( 27.54s elapsed)
GC time 15.79s ( 16.28s elapsed)
EXIT time 0.00s ( 0.00s elapsed)
Total time 41.25s ( 43.82s elapsed)
%GC time 38.3% (37.1% elapsed)
Alloc rate 562,483,714 bytes per MUT second
Productivity 61.7% of total user, 58.1% of total elapsed
Registering accelerate-0.9.0.0...
real 0m45.512s
user 0m43.370s
sys 0m1.100s
====================== GHC 7.0.3 =========================
24,541,831,600 bytes allocated in the heap
3,779,826,928 bytes copied during GC
107,669,136 bytes maximum residency (28 sample(s))
10,089,928 bytes maximum slop
275 MB total memory in use (0 MB lost due to fragmentation)
Generation 0: 46519 collections, 0 parallel, 9.59s, 9.59s elapsed
Generation 1: 28 collections, 0 parallel, 4.82s, 4.82s elapsed
Parallel GC work balance: -nan (0 / 0, ideal 1)
MUT time (elapsed) GC time (elapsed)
Task 0 (worker) : 0.00s ( 24.32s) 0.00s ( 0.00s)
Task 1 (worker) : 0.00s ( 24.37s) 0.00s ( 0.00s)
Task 2 (bound) : 22.80s ( 24.37s) 14.40s ( 14.41s)
SPARKS: 0 (0 converted, 0 pruned)
INIT time 0.00s ( 0.00s elapsed)
MUT time 22.81s ( 24.37s elapsed)
GC time 14.40s ( 14.41s elapsed)
EXIT time 0.00s ( 0.00s elapsed)
Total time 37.21s ( 38.78s elapsed)
%GC time 38.7% (37.2% elapsed)
Alloc rate 1,075,947,339 bytes per MUT second
Productivity 61.3% of total user, 58.8% of total elapsed
Registering accelerate-0.9.0.0...
real 0m40.254s
user 0m38.500s
sys 0m1.030s
================= GHC HEAD = 7.2 ===================
15,255,857,904 bytes allocated in the heap
3,268,823,408 bytes copied during GC
76,216,592 bytes maximum residency (35 sample(s))
2,914,432 bytes maximum slop
196 MB total memory in use (0 MB lost due to fragmentation)
Tot time (elapsed) Avg pause Max
pause
Gen 0 29181 colls, 0 par 7.54s 7.54s 0.0003s
0.0042s
Gen 1 35 colls, 0 par 4.56s 4.56s 0.1303s
0.2876s
Parallel GC work balance: -nan (0 / 0, ideal 1)
MUT time (elapsed) GC time (elapsed)
Task 0 (worker) : 0.00s ( 33.58s) 0.00s ( 0.00s)
Task 1 (worker) : 0.00s ( 33.58s) 0.00s ( 0.00s)
Task 2 (bound) : 19.74s ( 21.47s) 12.09s ( 12.10s)
SPARKS: 0 (0 converted, 0 dud, 0 GC'd, 0 fizzled)
INIT time 0.00s ( 0.00s elapsed)
MUT time 19.75s ( 21.47s elapsed)
GC time 12.10s ( 12.10s elapsed)
EXIT time 0.00s ( 0.00s elapsed)
Total time 31.85s ( 33.58s elapsed)
Alloc rate 772,436,650 bytes per MUT second
Productivity 62.0% of total user, 58.8% of total elapsed
Registering accelerate-0.9.0.0...
real 0m35.221s
user 0m33.700s
sys 0m0.770s
}}}
So I'm happy. It seems that `Sugar` is still a bit slow to compile
compared with 6.12.3, and 6.12 allocates less overall than either 7.0.3 or
HEAD. But the bottom line is good, so I'll close this ticket.
Simon
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/4856#comment:11>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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