On 28 Nov 2011, at 21:44, Bob Friesenhahn wrote: > On Mon, 28 Nov 2011, Peter Rosin wrote: >> >> My typical use case is "mid-sized" at a magnitude or so larger, and >> even there with a fork rate of approx 10-15 Hz as I'm seeing, it wouldn't >> be too harsh with a couple of extra forks - a minutes or so on the >> wall clock time. But it would really add to the pain on some >> (hypothetical?) large project with thousands of libtool invocations. >> That's all I'm saying, but *I* am not building any of those... > > Is Windows "fork" performance observed to improve linearly as processor cores > are added, or does it maintain pretty much a fixed rate? If it does not > improve linearly as processor cores are added, then the extra forks will > severely impact available performance of parallel builds. > > I have become used to seeing substantial speedup with 'make -j 4' on a > Windows system with four cores.
I just pushed the series containing this patch, but refactored to add only 3 additional forks per invocation, and with a patch to follow which might be good enough to eliminate even those 3 forks on windows machines. Cheers, -- Gary V. Vaughan (gary AT gnu DOT org)