On 28 Jan 2008, at 02:15, Peter Seebach wrote:
In message <email@hidden>,
Jonas Maebe wr
ites:
That's more or less true for Linux, but not for Mac OS X at least up
till 10.4.x (I haven't benchmarked on 10.5 yet). Compiling our
compiler with itself, which involves about 173 (v)fork+execs from a
single compiler run to assemble&link all the files, is 20% to 25%
slower with fork instead of vfork on a G4, and 35% to 40% on a G5
(32
bit processes in both cases) on 10.4.x. And for clarity: this is
relative to the entire time needed for compiling+assembling+linking
everything (on the G5: 24 vs 15 seconds), not some academic mbench-
like speed difference between the fork and vforks.
Yes. It does make a difference, but even so, the API is deprecated,
so even if this hurts performance a bit, it's still probably best to
avoid it whenever possible.
If it only hurt performance a bit I would never have changed the
code from using fork (which is what we used on all other *nix ports)
into using vfork in the first place. But a 25% to 40% slowdown
caused by 173 system calls in the process of compiling about 180
kloc is astronomical in my view.
