[Git][ghc/ghc][wip/T18023] 5 commits: rts: ProfHeap: Fix memory leak when not compiled with profiling
Ryan Scott
gitlab at gitlab.haskell.org
Tue Apr 7 23:48:06 UTC 2020
Ryan Scott pushed to branch wip/T18023 at Glasgow Haskell Compiler / GHC
Commits:
f38e8d61 by Daniel Gröber at 2020-04-07T02:00:05-04:00
rts: ProfHeap: Fix memory leak when not compiled with profiling
If we're doing heap profiling on an unprofiled executable we keep
allocating new space in initEra via nextEra on each profiler run but we
don't have a corresponding freeEra call.
We do free the last era in endHeapProfiling but previous eras will have
been overwritten by initEra and will never get free()ed.
Metric Decrease:
space_leak_001
- - - - -
bcd66859 by Sebastian Graf at 2020-04-07T02:00:41-04:00
Re-export GHC.Magic.noinline from base
- - - - -
3d2991f8 by Ben Gamari at 2020-04-07T18:36:09-04:00
simplifier: Kill off ufKeenessFactor
We used to have another factor, ufKeenessFactor, which would scale the
discounts before they were subtracted from the size. This was justified
with the following comment:
-- We multiple the raw discounts (args_discount and result_discount)
-- ty opt_UnfoldingKeenessFactor because the former have to do with
-- *size* whereas the discounts imply that there's some extra
-- *efficiency* to be gained (e.g. beta reductions, case reductions)
-- by inlining.
However, this is highly suspect since it means that we subtract a
*scaled* size from an absolute size, resulting in crazy (e.g. negative)
scores in some cases (#15304). We consequently killed off
ufKeenessFactor and bumped up the ufUseThreshold to compensate.
Adjustment of unfolding use threshold
=====================================
Since this removes a discount from our inlining heuristic, I revisited our
default choice of -funfolding-use-threshold to minimize the change in
overall inlining behavior. Specifically, I measured runtime allocations
and executable size of nofib and the testsuite performance tests built
using compilers (and core libraries) built with several values of
-funfolding-use-threshold.
This comes as a result of a quantitative comparison of testsuite
performance and code size as a function of ufUseThreshold, comparing
GHC trees using values of 50, 60, 70, 80, 90, and 100. The test set
consisted of nofib and the testsuite performance tests.
A full summary of these measurements are found in the description of
!2608
Comparing executable sizes (relative to the base commit) across all
nofib tests, we see that sizes are similar to the baseline:
gmean min max median
thresh
50 -6.36% -7.04% -4.82% -6.46%
60 -5.04% -5.97% -3.83% -5.11%
70 -2.90% -3.84% -2.31% -2.92%
80 -0.75% -2.16% -0.42% -0.73%
90 +0.24% -0.41% +0.55% +0.26%
100 +1.36% +0.80% +1.64% +1.37%
baseline +0.00% +0.00% +0.00% +0.00%
Likewise, looking at runtime allocations we see that 80 gives slightly
better optimisation than the baseline:
gmean min max median
thresh
50 +0.16% -0.16% +4.43% +0.00%
60 +0.09% -0.00% +3.10% +0.00%
70 +0.04% -0.09% +2.29% +0.00%
80 +0.02% -1.17% +2.29% +0.00%
90 -0.02% -2.59% +1.86% +0.00%
100 +0.00% -2.59% +7.51% -0.00%
baseline +0.00% +0.00% +0.00% +0.00%
Finally, I had to add a NOINLINE in T4306 to ensure that `upd` is
worker-wrappered as the test expects. This makes me wonder whether the
inlining heuristic is now too liberal as `upd` is quite a large
function. The same measure was taken in T12600.
Wall clock time compiling Cabal with -O0
thresh 50 60 70 80 90 100 baseline
build-Cabal 93.88 89.58 92.59 90.09 100.26 94.81 89.13
Also, this change happens to avoid the spurious test output in
`plugin-recomp-change` and `plugin-recomp-change-prof` (see #17308).
Metric Decrease:
hie002
T12234
T13035
T13719
T14683
T4801
T5631
T5642
T9020
T9872d
T9961
Metric Increase:
T12150
T12425
T13701
T14697
T15426
T1969
T3064
T5837
T6048
T9203
T9872a
T9872b
T9872c
T9872d
haddock.Cabal
haddock.base
haddock.compiler
- - - - -
255418da by Sylvain Henry at 2020-04-07T18:36:49-04:00
Modules: type-checker (#13009)
Update Haddock submodule
- - - - -
6c697c24 by Ryan Scott at 2020-04-07T19:45:59-04:00
Use conLikeUserTyVarBinders to quantify field selector types
This patch:
1. Writes up a specification for how the types of top-level field
selectors should be determined in a new section of the GHC User's
Guide, and
2. Makes GHC actually implement that specification by using
`conLikeUserTyVarBinders` in `mkOneRecordSelector` to preserve the
order and specificity of type variables written by the user.
Fixes #18023.
- - - - -
30 changed files:
- CODEOWNERS
- compiler/GHC.hs
- compiler/GHC/Cmm/Expr.hs
- compiler/GHC/Cmm/Node.hs
- compiler/GHC/Core.hs
- compiler/GHC/Core/Arity.hs
- compiler/GHC/Core/Class.hs
- compiler/GHC/Core/Coercion.hs
- compiler/GHC/Core/Coercion/Axiom.hs
- compiler/GHC/Core/Coercion/Opt.hs
- compiler/GHC/Core/ConLike.hs
- compiler/GHC/Core/DataCon.hs
- compiler/GHC/Core/FamInstEnv.hs
- compiler/GHC/Core/InstEnv.hs
- compiler/GHC/Core/Lint.hs
- compiler/GHC/Core/Op/CSE.hs
- compiler/GHC/Core/Op/OccurAnal.hs
- compiler/GHC/Core/Op/Simplify.hs
- compiler/GHC/Core/Op/Specialise.hs
- compiler/GHC/Core/PatSyn.hs
- compiler/GHC/Core/Predicate.hs
- compiler/GHC/Core/Rules.hs
- compiler/GHC/Core/TyCo/FVs.hs
- compiler/GHC/Core/TyCo/Ppr.hs
- compiler/GHC/Core/TyCo/Rep.hs
- compiler/GHC/Core/TyCon.hs
- compiler/GHC/Core/Type.hs
- compiler/GHC/Core/Unfold.hs
- compiler/GHC/Core/Unify.hs
- compiler/GHC/CoreToStg/Prep.hs
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/d3706e35310d150f6ecb4eeade0c3e1b7108d9cf...6c697c24cda33fb7ec5b9ff36188584ea8d3e81a
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/d3706e35310d150f6ecb4eeade0c3e1b7108d9cf...6c697c24cda33fb7ec5b9ff36188584ea8d3e81a
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