Re: [Haskell-cafe] Slow mvar when compiled with threaded

On 01/10/2014 01:03 AM, Bob Ippolito wrote:

The bad news is that the fix is to compile it with GHC HEAD (~7.8, I built ec4af3f), which has the new Mio high-performance multicore IO manager [1]. Apparently the old IO manager wasn't well suited to this use case.

With the latest GHC, the -threaded version outperforms the single threaded version, and the numbers for both are better than with GHC 7.6.3.

Thanks. Glad to hear that!