Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 ---+ Reporter: simonmar | Owner: igloo Type: bug | Status: closed Priority: highest | Milestone: 7.6.1 Component: Compiler |Version: 7.5 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: Compile-time performance bug | Difficulty: Unknown Testcase:| Blockedby: Blocking:|Related: ---+ Changes (by pcapriotti): * status: merge = closed * resolution: = fixed Comment: Merged as 1363c32a0d5b79c846530fa16d09076d02f29d1c. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:14 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: igloo Type: bug | Status: merge Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Changes (by pcapriotti): * status: new = merge Comment: Residency is now only 25% bigger in HEAD. Closing. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:13 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner: simonpj
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Comment(by simonpj@…):
commit cd627bcfda713efa63b7f5290c84a5077f4976f9
{{{
Author: Simon Peyton Jones simo...@microsoft.com
Date: Fri Jul 20 20:07:51 2012 +0100
Do calcUnfoldingGuidance on the *non* occ-analysed RHS
See Note [Calculate unfolding guidance on the non-occ-anal'd
expression]
This makes a big difference to residency (530M vs over 800M when
compiling
Cabal).
This fixes the majority of the regression in Trac #6104
compiler/coreSyn/CoreUnfold.lhs | 79
+-
1 files changed, 52 insertions(+), 27 deletions(-)
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:11
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: igloo Type: bug | Status: new Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Changes (by simonpj): * owner: simonpj = igloo Comment: I claim we are done here. Paolo or Ian, can you check and close? Compiling Cabal seems like a good perf test, if an expensive one. Maybe we should add it as a perf regression test? Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:12 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner: simonpj
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Comment(by simonpj):
There doesn't seem to be much of a difference on `CopyFile`, at least not
now. Here's the size of the .o file:
{{{
text data bss dec hex filename
With 7.4.1 6480760 072401c48 T6104.o
With HEAD 4769704 054731561 T6104.o
}}}
So HEAD generates less code, not more. The compiler does allocate a bit
more, but not much:
{{{
7.4.1 with -O on CopyFile.hs
[1 of 1] Compiling CopyFile ( T6104.hs, T6104.o )
146,131,584 bytes allocated in the heap
67,295,032 bytes copied during GC
16,663,568 bytes maximum residency (6 sample(s))
1,330,480 bytes maximum slop
33 MB total memory in use (0 MB lost due to fragmentation)
HEAD with -O on CopyFile.hs
[1 of 1] Compiling CopyFile ( T6104.hs, T6104.o )
156,295,232 bytes allocated in the heap
71,474,496 bytes copied during GC
16,357,872 bytes maximum residency (7 sample(s))
1,451,648 bytes maximum slop
32 MB total memory in use (0 MB lost due to fragmentation)
}}}
I suppose the next thing is to try compiling Cabal.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:8
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner: simonpj
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Comment(by simonpj):
Interface file size:
{{{
GHC 7.4.1 -O -rw-rw-r-- 1 simonpj GHC 5983 Jul 16 15:21 T6104.hi
HEAD -rw-rw-r-- 1 simonpj GHC 10487 Jul 16 14:08 T6104.hi
}}}
So, yes, the interface file is a lot bigger. Looking more closely, this
seems largely accidental. The code in HEAD is broken into more functions,
each of which is individually small enough to be below the inlining-
creation threshold.
I compiled Cabal with -O, and compared the total size (with `ls -l`) of
the `.o` files and `.hi` files with both compilers:
{{{
HEAD change over 7.4.1
.o file size-6%
.hi file size +8%
}}}
So yes, interface file size is up, but not massively, and .o file size is
down.
This does not seem to account for the originally-reported doubling of
residency! And (I've checked) that doubling is still happening.
Conclusion: I don't think it's just bigger interface files. I there is
some other space leak too.
Simon
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:9
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: simonpj Type: bug | Status: new Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Comment(by simonpj): Paulo, might you produce a space profile of 7.4.1 and HEAD compiling Cabal? Thanks Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: simonpj Type: bug | Status: new Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Comment(by igloo): #4138 is another inlining-heuristic-related ticket. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner: igloo
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Comment(by igloo):
Most of the regression comes from this patch:
{{{
commit 980372f357667c1ba63b28acbf5798826890b7a5
Author: Simon Peyton Jones simo...@microsoft.com
Date: Wed May 9 16:22:49 2012 +0100
Re-do the function application discount (fixes Trac #6048)
}}}
(the SimplCont patches also made things a bit worse, but I haven't looked
into that at all).
I think that the problem is more/bigger inlinings, rather than a space
leak in GHC itself. I'll attach `CopyFile.hs`, and `before.txt` and
`after.txt` showing the interface files before and after this patch is
applied.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:5
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: igloo Type: bug | Status: new Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Changes (by igloo): * owner: = igloo -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner:
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Comment(by simonmar):
I've narrowed this down to something that happened around May 8-10. I'm
seeing a roughly 10% increase in compile times that was in the May 10
nightly build compared to the May 8 nightly build (I've unpacked the
builds to check).
e.g. compiling Cabal with -O and ghc-20120508:
{{{
51,777,170,264 bytes allocated in the heap
10,213,181,272 bytes copied during GC
174,111,968 bytes maximum residency (57 sample(s))
6,843,024 bytes maximum slop
496 MB total memory in use (0 MB lost due to fragmentation)
Tot time (elapsed) Avg pause Max
pause
Gen 0 100232 colls, 0 par 25.37s 25.36s 0.0003s
0.0040s
Gen 157 colls, 0 par 13.46s 13.46s 0.2362s
0.5846s
INITtime0.00s ( 0.00s elapsed)
MUT time 58.57s ( 61.82s elapsed)
GC time 38.82s ( 38.82s elapsed)
EXITtime0.00s ( 0.00s elapsed)
Total time 97.40s (100.65s elapsed)
}}}
and with ghc-20120510:
{{{
55,714,073,216 bytes allocated in the heap
11,751,752,512 bytes copied during GC
288,316,064 bytes maximum residency (51 sample(s))
8,407,960 bytes maximum slop
809 MB total memory in use (0 MB lost due to fragmentation)
Tot time (elapsed) Avg pause Max
pause
Gen 0 107660 colls, 0 par 28.91s 28.90s 0.0003s
0.0044s
Gen 151 colls, 0 par 16.56s 16.56s 0.3247s
1.0106s
INITtime0.00s ( 0.00s elapsed)
MUT time 60.13s ( 63.20s elapsed)
GC time 45.47s ( 45.46s elapsed)
EXITtime0.00s ( 0.00s elapsed)
Total time 105.60s (108.67s elapsed)
}}}
we don't have a May 9 build because the change from mtl to transformers
broke it.
I've had a look at the patches that went in around that time, and these
are the only possible culprits as far as I can tell:
{{{
commit f7e246b50a33c329e9730296f7a342e03bc3db72
Merge: 4b089db... ff10612...
Author: Simon Peyton Jones simo...@microsoft.com
Date: Wed May 9 15:50:54 2012 +0100
Merge branch 'ghc-new-flavor'
commit 4bbd6baee066b906ed93a0659205ecbffdbd0954
Author: Simon Peyton Jones simo...@microsoft.com
Date: Fri May 4 23:02:46 2012 +0100
Simplify the SimplCont data type
commit e08cad76e8a434aca42996f79fc8bb790f291570
Author: Simon Peyton Jones simo...@microsoft.com
Date: Tue May 8 10:25:22 2012 +0100
Wibbles to 'simplify the SimplCont data type'
commit 2112f43c466935818a371c53c706608cfa069d01
Author: Simon Peyton Jones simo...@microsoft.com
Date: Wed May 9 11:06:44 2012 +0100
Be a little less aggressive about inlining (fixes Trac #5623)
commit 980372f357667c1ba63b28acbf5798826890b7a5
Author: Simon Peyton Jones simo...@microsoft.com
Date: Wed May 9 16:22:49 2012 +0100
Re-do the function application discount (fixes Trac #6048)
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:3
GHC http://www.haskell.org/ghc/
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4
-+--
Reporter: simonmar | Owner:
Type: bug | Status: new
Priority: highest | Milestone: 7.6.1
Component: Compiler | Version: 7.5
Keywords:| Os: Unknown/Multiple
Architecture: Unknown/Multiple | Failure: Compile-time performance bug
Difficulty: Unknown |Testcase:
Blockedby:|Blocking:
Related:|
-+--
Changes (by pcapriotti):
* owner: pcapriotti =
Comment:
Here are some heap profiler reports comparing GHC HEAD with 7.4 when
compiling
Cabal and the single Cabal module Distribution/Simple/Setup.hs.
They are obtained by running:
{{{
ghc -O --make Distribution.Simple +RTS -hc
}}}
and
{{{
ghc -O -fforce-recomp --make Distribution/Simple/Setup.hs +RTS -hc
}}}
respectively, with both compilers built with `-prof -auto` on
`compiler/simplCore/Simplify.lhs`, where the leak seems to be located.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:2
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Re: [GHC] #6104: Regression: space leak in HEAD vs. 7.4
#6104: Regression: space leak in HEAD vs. 7.4 -+-- Reporter: simonmar | Owner: pcapriotti Type: bug | Status: new Priority: highest | Milestone: 7.6.1 Component: Compiler | Version: 7.5 Keywords:| Os: Unknown/Multiple Architecture: Unknown/Multiple | Failure: Compile-time performance bug Difficulty: Unknown |Testcase: Blockedby:|Blocking: Related:| -+-- Changes (by pcapriotti): * owner: = pcapriotti -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/6104#comment:1 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
