Messages in this thread |  | | Date | Fri, 25 Aug 2006 11:11:13 +0200 (MEST) | | From | Jan Engelhardt <> | | Subject | Re: [PATCH 0/4] Compile kernel with -fwhole-program --combine |
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>> >> Compiling files on their own (`make drivers/foo/bar.o`) seems to make >> >> the optimization void. Sure, most people don't stop compiling in >> >> between. Just a note >> > >> >Actually I'm not entirely sure what you write is true. It'll _build_ >> >fs/jffs2/read.o, for example, but it still won't then use it when I make >> >the kernel -- it'll just use fs/jffs2/jffs2.o which is built from all >> >the C files with --combine. So the optimisation isn't lost. >> >> Umm then it spends double the time in compilation, doing: >> >> read.o <- read.c >> foo.o <- foo.c >> bar.o <- bar.c >> built-in.o <- read.c foo.c bar.c > >Only if you invoke make explicitly for read.o, foo.o and bar.o. If you >just type 'make' then it won't build those.
That's what I meant. Assume I explicitly built read.o foo.o and bar.o. If I then run the regular make, it will rerun gcc for read.c foo.c and bar.c rather than using the already-created .o files for linking.
Jan Engelhardt -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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