Hello, On Mon, Dec 23, 2019 at 2:55 PM Andrii Nakryiko <andrii.nakryiko@xxxxxxxxx> wrote: > > On Sun, Dec 22, 2019 at 9:45 PM Andrii Nakryiko > <andrii.nakryiko@xxxxxxxxx> wrote: > > > > On Sun, Dec 22, 2019 at 7:05 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote: > > > > > > I got the following error when I tried to build perf on a read-only > > > filesystem with O=dir option. > > > > > > $ cd /some/where/ro/linux/tools/perf > > > $ make O=$HOME/build/perf > > > ... > > > CC /home/namhyung/build/perf/lib.o > > > /bin/sh: bpf_helper_defs.h: Read-only file system > > > make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 1 > > > make[2]: *** [Makefile.perf:778: /home/namhyung/build/perf/libbpf.a] Error 2 > > > make[2]: *** Waiting for unfinished jobs.... > > > LD /home/namhyung/build/perf/libperf-in.o > > > AR /home/namhyung/build/perf/libperf.a > > > PERF_VERSION = 5.4.0 > > > make[1]: *** [Makefile.perf:225: sub-make] Error 2 > > > make: *** [Makefile:70: all] Error 2 > > > > > > It was becaused bpf_helper_defs.h was generated in current directory. > > > Move it to OUTPUT directory. > > > > > > Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx> > > > --- > > > > Looks good, thanks! > > just one minor thing: bpf_helper_defs.h has to be added to .gitignore > under selftests/bpf now > > > > > Tested-by: Andrii Nakryiko <andriin@xxxxxx> > > Acked-by: Andrii Nakryiko <andriin@xxxxxx> Thanks a lot for the review, I'll send v3 soon Thanks Namhyung