On Tue, Jan 24, 2017 at 09:42:35AM +0100, Olivier MATZ wrote: > Hi Keith, > > On Mon, 23 Jan 2017 17:50:27 +0000, "Wiles, Keith" > <keith.wi...@intel.com> wrote: > > > On Jan 23, 2017, at 10:18 AM, Olivier Matz <olivier.m...@6wind.com> > > > wrote: > > > > > > Hi Ferruh, > > > > > > On Sun, 22 Jan 2017 01:50:34 +0000, Ferruh Yigit > > > <ferruh.yi...@intel.com> wrote: > > >> make config dependency resolving was always running serial, > > >> parallelize it for better performance. > > >> > > >> $ time make T=x86_64-native-linuxapp-gcc config > > >> real 0m12.633s > > >> > > >> $ time make -j8 T=x86_64-native-linuxapp-gcc config > > >> real 0m1.826s > > >> > > >> Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com> > > > > > > I have a patch that fix the same issue (configuration takes to > > > long), but done differently. It is more intrusive, since it rework > > > the way DEPDIRS are used, but it does not require to use -j. > > > > I tested the patch and the performance is very quick and seems to > > work very nicely. I have not looked at the other patch yet are they > > both compatible and could be combined or not? > > No, I don't think they could be combined. > > Ferruh's approach looks less risky, since it's a parallelization > of the config. My approach changes the way dependencies are processed, > and also how they are declared. I think it's faster, but more intrusive. > I think we may hit a case of diminishing returns. On my system, the config time goes from 12 seconds down to less than 1 second (large amounts of parallelism). Even with limiting parallelism to just 4 make processes, the time for config drops to 3 seconds. I don't see huge value in trying to shave off any more time than that, given the amount of extra complexity involved.
/Bruce
