On Wed, Oct 29, 2008 at 11:59:06AM -0700, Paul Querna wrote: > Is COW ability of fork important enough with modern memory and operating > systems, to maintain two significantly different code paths for spawning > children processes?
I looked at a stock 2.2 install (x86_64) with most modules built as DSOs, and it looks like there's about 1-2MB of anon heap allocated. (look at pmap or /proc/$PID/maps if anybody else wants to compare) So... I would guess the answer is, "it depends", if that is a reasonable estimate at the fork benefit. If you expect people to be doing those insane 50K process tricks as are possible with prefork, then 50K*1MB is a huge additional overhead, yes. If not, then I'd guess it's lost in the noise. I think the far bigger difference between Windows and Unix on this front is fd/HANDLE inheritance though. Unless you want to get into passing fds over AF_UNIX sockets on Unix (please no) then there is going to remain a major disparity in how an MPM operates between the two platforms, and you might as well keep the stuff Unix does well, no? Regards, Joe
