#3796: GHC 6.12 dependency checking many times slower than 6.10
-------------------------------------------+--------------------------------
Reporter: sunrayser | Owner: simonmar
Type: bug | Status: new
Priority: high | Milestone: 6.12.2
Component: Compiler | Version: 6.12.1
Resolution: | Keywords:
Difficulty: | Os: Linux
Testcase: | Architecture: x86
Failure: Compile-time performance bug |
-------------------------------------------+--------------------------------
Comment (by simonpj):
Simon's looked into this:
{{{
Thu Dec 31 16:46:51 GMT 2009 Simon Marlow <[email protected]>
* Rolling back: Make FastString thread-safe.
Ignore-this: 8f21b256b0c86d167f8f6984d2b27a87
This patch was the cause of the compile-time performance regression in
#3796. My guess is that it is due to the use of unsafePerformIO which
traverses the stack up to the first update frame, and perhaps we have
a deep stack when reading the dictionary from a .hi file. In any
case, since we're not relying on thread safety for FastStrings, I
think the safest thing to do is back this out until we can investigate
further.
}}}
I'm not sure if we can close the ticket. Simon?
S
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3796#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler_______________________________________________
Glasgow-haskell-bugs mailing list
[email protected]
http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
