On Mon, Mar 18, 2019 at 02:47:13PM -0700, 'Nick Desaulniers' via Clang Built Linux wrote: > On Mon, Mar 18, 2019 at 2:10 PM Matthias Kaehlcke <mka@xxxxxxxxxxxx> wrote: > > > > The clang option -Oz enables *aggressive* optimization for size, > > which doesn't necessarily result in smaller images, but can have > > negative impact on performance. Switch back to the less aggressive > > -Os. > > > > This reverts commit 6748cb3c299de1ffbe56733647b01dbcc398c419. > > Does scripts/checkpatch.pl complain about this format (full sha, no > title)? Nope, for reverts checkpatch is happy with it, I suppose because by default the subject of the reverted patch is part of the revert's subject. > Not sure that necessitates a v2, but if so would be good to > mention that Clang generates excessive calls into libgcc/compiler-rt > at -Oz. Thanks for the patch and the discussion/sanity check. I can send a v2 if 'needed'. > Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Thanks! Matthias > > > > Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx> > > Signed-off-by: Matthias Kaehlcke <mka@xxxxxxxxxxxx> > > --- > > Makefile | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/Makefile b/Makefile > > index 9ef547fc7ffe..191f3ce3cb5e 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -667,7 +667,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, format-overflow) > > KBUILD_CFLAGS += $(call cc-disable-warning, int-in-bool-context) > > > > ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE > > -KBUILD_CFLAGS += $(call cc-option,-Oz,-Os) > > +KBUILD_CFLAGS += -Os > > else > > KBUILD_CFLAGS += -O2 > > endif > > >
