With the code I shown here it would be still an all or nothing generation of Make.dep as I remove all .d files. I didn't want to change that to avoid breaking anything. Do you intend to create a PR in this regard? Otherwise I can create one with this code
Best, Matias On Sun, Sep 27, 2020, at 10:42, Xiang Xiao wrote: > Yes, this is what we are considering to change. It desn't only improve > the parallelization, but also avoids generating the full library(e.g. > libc) dependency if the user just changes one source file. > > On Sun, Sep 27, 2020 at 10:55 AM Matias N. <mat...@imap.cc> wrote: > > > > Hi, > > as a test I changed the depend generation to main nuttx Makefiles to this: > > > > %.dd: %.c > > $(Q) $(MKDEP) $(DEPPATH) "$(CC)" -- $(CFLAGS) -- $< > $@ > > > > makedepfile: $(patsubst %.c,%.dd,$(SRCS)) > > @for f in $^; do cat $$f; done > Make.dep > > $(call DELFILE, $^) > > > > .depend: Makefile $(SRCS) $(TOPDIR)$(DELIM).config > > $(Q) $(MAKE) makedepfile > > $(Q) touch $@ > > > > This allows to parallelize each MKDEP call, which currently is done once > > with all $(SRCS) together. > > > > Original: > > make depend -j8 11.29s user 6.67s system 106% cpu 16.888 total > > Parallel: > > make depend -j8 14.34s user 5.73s system 286% cpu 6.994 total > > > > So about 10 seconds less and much more CPU utilized. > > > > What do you think of the change? Any reason not to do this? > > > > Best, > > Matias >
