http://bugs.winehq.org/show_bug.cgi?id=30148
--- Comment #20 from julusp@gmail.com 2012-04-08 17:57:21 CDT --- I made better benchmark (which actually read the mmaped file) so the results more believable:
MAP_PRIVATE OSX LINUX 1000 mmaps 4KB blocks: 22483ms 20ms 1000 mmaps 64KB blocks: 22381ms 264ms 1000 mmaps 1024KB blocks: 24862ms 4227ms
MAP_SHARED OSX LINUX 1000 mmaps 4KB blocks: 18ms 19ms 1000 mmaps 64KB blocks: 170ms 268ms 1000 mmaps 1024KB blocks: 2730ms 4302ms
And I submitted bug to Apple. We'll see if they will fix or come up with another solution.