On 12.02.2016 17:06, Arnd Bergmann wrote: > Enabling CONFIG_GCOV_PROFILE_ALL produces us a lot of warnings like > > lib/lz4/lz4hc_compress.c: In function 'lz4_compresshcctx': > lib/lz4/lz4hc_compress.c:514:1: warning: the frame size of 1504 bytes is larger than 1024 bytes [-Wframe-larger-than=] > > After some investigation, I found that this behavior started with gcc-4.9, > and opened https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69702. > A suggested workaround for it is to use the -fno-tree-loop-im > flag that turns off one of the optimization stages in gcc, so the > code runs a little slower but does not use excessive amounts > of stack. > > We could make this conditional on the gcc version, but I could not > find an easy way to do this in Kbuild and the benefit would be > fairly small, given that most of the gcc version in production are > affected now. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> -fno-tree-loop-im seems to have been available for long enough in GCC (starting with GCC4) to make this part of the default gcov compile flags. Acked-by: Peter Oberparleiter <oberpar@xxxxxxxxxxxxxxxxxx> > --- > Makefile | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/Makefile b/Makefile > index 352f55ccc54e..6bb89728a9d1 100644 > --- a/Makefile > +++ b/Makefile > @@ -364,7 +364,7 @@ AFLAGS_MODULE = > LDFLAGS_MODULE = > CFLAGS_KERNEL = > AFLAGS_KERNEL = > -CFLAGS_GCOV = -fprofile-arcs -ftest-coverage > +CFLAGS_GCOV = -fprofile-arcs -ftest-coverage -fno-tree-loop-im > CFLAGS_KCOV = -fsanitize-coverage=trace-pc > > -- Peter Oberparleiter Linux on z Systems Development - IBM Germany -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
