http://bugs.winehq.org/show_bug.cgi?id=21423
--- Comment #5 from Dan Kegel dank@kegel.com 2010-01-28 15:10:40 --- Both the file open (where it's just a trivial C program opening a lot of trivial files) and file include (where the program is the C compiler compiling a lot of trivial files) benchmarks show about a 2x slowdown on Wine as opposed to Windows on the same hardware (roughly 2 seconds vs. 1 second).
Adding a Sleep(0) to the beginning of CreateFile() in kernel32 did not change the results much. Adding Sleep(1) (which may involve several wineserver round-trips) resulted in a 6x slowdown in both benchmarks.
This seems consistent with "file opens are slow in Wine" and with the high CPU report for wineserver in 'top' (which I guess is mostly system time, judging by oprofile).
Well, well, Mr. Bond. How do you expect to speed that up?