#14066: Skolem escape at the kind level
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Reporter: simonpj | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Compiler | Version: 8.0.1
Keywords: | Operating System: Unknown/Multiple
Architecture: | Type of failure: None/Unknown
Unknown/Multiple |
Test Case: | Blocked By:
Blocking: | Related Tickets:
Differential Rev(s): | Wiki Page:
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This program should be rejected
{{{
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE PolyKinds #-}
{-# LANGUAGE TypeInType #-}
{-# LANGUAGE KindSignatures #-}
module Foo2 where
import Data.Kind ( Type )
import Data.Type.Equality
import Data.Proxy
import GHC.Exts
data SameKind :: k -> k -> Type
f (x :: Proxy a) = let g :: forall k (b :: k). SameKind a b
g = undefined
in
()
}}}
But
* 8.0 rejects it, with an unhelpful message
* 8.2 accepts it, and the result satisfies Core Lint
* HEAD accepts it, and produces a Core Lint Error
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14066>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
#14981: GHC parallel GC is not doing well on modern many-core machine
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Reporter: varosi | Owner: (none)
Type: bug | Status: new
Priority: normal | Milestone:
Component: Runtime | Version: 8.4.1
System |
Keywords: | Operating System: Unknown/Multiple
Architecture: | Type of failure: None/Unknown
Unknown/Multiple |
Test Case: | Blocked By:
Blocking: | Related Tickets:
Differential Rev(s): | Wiki Page:
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I'm testing a small ray-tracer on different many-core machines, like x64
88 core and Aarch64 96 core (on https://packet.net) Parallel GC seems to
have throughput problems on more than 24-32 cores.
See this Reddit thread about -
https://www.reddit.com/r/haskell/comments/85vwlq/our_lovely_ghc_parallel_gc…
There you may find .eventlog file and PNG with a screenshot.
May be it's time to resurrect Concurrent GC project again?
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14981>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
