Magnus Holmgren wrote:
> I'm trying to figure out why Cygwin build things so much slower on one
> computer I have. We're talking about more than 3 times slower on a
> computer that ought to be a bit faster (Athlon64 at 2.2-2.4 GHz,
> compared to a Pentium M at 1.8 GHz).
After some more digging - and a bit of feedback off-list - I get the
feeling (in the cases I've noticed at least) that the speed difference
is mainly explained by the following reasons (in no particular order):
* fork is expensive.
* vfork is just a wrapper for fork on cygwin.
* fork is much more expensive on AMD than on Intel.
The third one is the one I'm most unsure about, as I only really have
data about one Intel architecture (the Pentium M). But on the AMD
system, the page fault delta (as reported by Process Explorer) during a
build is a little more than 10,000 per second, while on the Intel
system, the page fault delta can go to 30,000 per second.
(Anyone who knows how SFU implements (v)fork? :)
Magnus
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