On Tue, Jan 24, 2017 at 12:15:06PM +0000, Bruce Richardson wrote: > On Tue, Jan 24, 2017 at 05:10:15PM +0530, Jerin Jacob wrote: > > On Mon, Jan 23, 2017 at 06:19:13PM +0100, Olivier Matz wrote: > > > Before this patch, the management of dependencies between directories > > > had several issues: > > > > > > - the generation of .depdirs, done at configuration is slow: it can take > > > more than one minute on some slow targets (usually ~10s on a standard > > > PC). > > > > > > - for instance, it is possible to expressed a dependency like: > > > - app/foo depends on lib/librte_foo > > > - and lib/librte_foo depends on app/bar > > > But this won't work because the directories are traversed with a > > > depth-first algorithm, so we have to choose between doing 'app' before > > > or after 'lib'. > > > > > > - the script depdirs-rule.sh is too complex. > > > > > > - we cannot use "make -d" for debug, because the output of make is used > > > for > > > the generation of .depdirs. > > > > > > This patch moves the DEPDIRS-* variables in the upper Makefile, making > > > the dependencies much easier to calculate. A DEPDIRS variable is still > > > used to process library dependencies in LDLIBS. > > > > > > After this commit, "make config" is almost immediate. > > > > > > Signed-off-by: Olivier Matz <olivier.m...@6wind.com> > > > > Tested both approach on ThunderX. This patch looks better > > > > Tested-by: Jerin Jacob <jerin.ja...@caviumnetworks.com> > > > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc > > Configuration done > > > > real 0m18.112s > > user 0m2.810s > > sys 0m0.660s > > > > ➜ [master]GB-2S [dpdk-master] $ pwclient git-am 19859 > > Applying patch #19859 using 'git am' > > Description: [dpdk-dev] mk: parallelize make config > > Applying: mk: parallelize make config > > > > ➜ [master]GB-2S [dpdk-master] $ rm -rf build > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc -j 8 > > Configuration done > > > > real 0m2.812s > > user 0m3.020s > > sys 0m0.870s > > > > ➜ [master]GB-2S [dpdk-master] $ rm -rf build > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc -j 16 > > Configuration done > > > > real 0m1.748s > > user 0m3.040s > > sys 0m1.020s > > > > ➜ [master]GB-2S [dpdk-master] $ rm -rf build > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc -j 32 > > Configuration done > > > > real 0m1.422s > > user 0m3.380s > > sys 0m1.080s > > > > ➜ [master]GB-2S [dpdk-master] $ pwclient git-am 19918 > > Applying patch #19918 using 'git am' > > Description: [dpdk-dev] mk: optimize directory dependencies > > Applying: mk: optimize directory dependencies > > > > ➜ [master]GB-2S [dpdk-master] $ rm -rf build > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc > > Configuration done > > > > real 0m0.064s > > user 0m0.000s > > sys 0m0.000s > > ➜ [master]GB-2S [dpdk-master] $ rm -rf build > > ➜ [master]GB-2S [dpdk-master] $ time make config > > T=arm64-thunderx-linuxapp-gcc -j 8 > > Configuration done > > > > real 0m0.055s > > user 0m0.000s > > sys 0m0.000s > > > > I agree that Olivier's patch is faster. However, I think I prefer having > the library dependencies in the makefiles for the libs themselves rather > than up a level. Given that we are only looking at ~2second of a > difference here in your tests - assuming -j flag - what is the actual > build time differences? My suspicion is that after Ferruh's simpler
Without patch - 18sec With patch -j1 - 18 sec With patch -j2 - 9.2 sec With patch -j4 - 4.9 sec With patch -j8 - 2.8 sec With patch -j16 - 1.7 sec With patch -j32 - 1.4 sec > patch is applied, the config time becomes such a small part of the > build, that the extra benefits from Oliviers work is not worth the extra > complexity. The low-end embedded SoCs (SoC with 2 to 4 cores) will be get benefited out of bring this extra complexity.My take is, if it is manageable complexity then take the most optimized one.
