#7602: Threaded RTS performing badly on recent OS X (10.8?) -------------------------------+-------------------------------------------- Reporter: simonmar | Owner: thoughtpolice Type: bug | Status: new Priority: normal | Milestone: _|_ Component: Runtime System | Version: 7.7 Keywords: | Os: MacOS X Architecture: x86_64 (amd64) | Failure: None/Unknown Difficulty: Unknown | Testcase: Blockedby: 7678 | Blocking: Related: | -------------------------------+-------------------------------------------- Comment(by simonmar): Ok, so an inline `pthread_getspecific` is good, but it's still not ideal, because the compiler can't see the code inside the inline asm. Multiple references to the TLS variable should not cause repeated reads, but with the inline `pthread_getspecific`, they will. However, this can be worked around in the code by loading the TLS variable into a local once at the start of the function. I wouldn't object to this, it's less invasive than passing around the TLS variable as a parameter everywhere. But we should peer at the asm before and after to make sure it's doing what we expect. Stealing the WebKit-reserved slot would probably work for now, until some library developer has the same idea, and then we have a bizarre bug waiting to happen. I suppose I slightly prefer to use gcc for now, since we know it works, has good performance, and doesn't have this infelicity. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7602#comment:16 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler