Hi Peter, On Mon, Mar 18, 2019 at 06:16:04PM +0100, Peter Zijlstra wrote: > On Mon, Mar 18, 2019 at 10:09:37AM -0700, Nick Desaulniers wrote: > > On Fri, Mar 15, 2019 at 3:29 PM Matthias Kaehlcke <m...@chromium.org> wrote: > > > On Fri, Mar 15, 2019 at 02:31:09PM -0700, 'Nick Desaulniers' via Clang > > > Built Linux wrote: > > > > Is there a config I can set to reproduce this, in order to help > > > > test? > > > > > > I encountered it with a Chrome OS specific configuration, but a > > > defconfig should do. > > > > defconfig selects CONFIG_OPTIMIZE_FOR_PERFORMANCE=y. I needed to > > select CONFIG_CC_OPTIMIZE_FOR_SIZE=y to repro. My CI is simply > > running defconfigs, which is why I didn't catch this. > > I suspect the right fix is to make clang use -Os and abolish that -Oz > madness.
You have a point, enabling -Oz (aggressive optimization for size) doesn't seem a good choice for the entire kernel. I'll send a patch to change it (back) to -Os. Matthias
