On Saturday 17 October 2015 07:06 PM, Alexey Brodkin wrote: > Perf uses atomic options and so it is required to have atomics enabled > in toolchain. > > In case of ARC atomics are enabled by default for ARCv2 but disabled for > ARCv1. Now we explicitly enable atomics for either ARC achitecture > version so perf could be successfully built. > > Currently on attempt to build perf for ARCv1 you'll see tons of: > ----------------->8----------------- > undefined reference to `__sync_add_and_fetch_4' > ----------------->8----------------- > > Still note if ARCv1 CPU is configured without LL/SC perf will crash on > execution once "llock" instruction is attempted to be executed.
Ok this fixes ARCompact - assuming it will have LL/SC. We do have old SoCs w/o that support. So what we are saying is that any arch (or a configuration thereof) which doesn't support atomic r-m-w can't even build perf now - that sucks ! A better way would be to do feature test for __sync_xyz and make atomic_xxx wrappers call __sync_xyz) vs. an empty stub. So atleast such arches can build and do "some" perf work ! -Vineet > Cc: Vineet Gupta <vgu...@synopsys.com> > Cc: Peter Zijlstra <pet...@infradead.org> > Cc: Arnaldo Carvalho de Melo <a...@kernel.org> > Signed-off-by: Alexey Brodkin <abrod...@synopsys.com> > --- > tools/perf/config/Makefile | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/tools/perf/config/Makefile b/tools/perf/config/Makefile > index 38a0853..dc7c0a8 100644 > --- a/tools/perf/config/Makefile > +++ b/tools/perf/config/Makefile > @@ -47,6 +47,11 @@ ifeq ($(ARCH),arm64) > LIBUNWIND_LIBS = -lunwind -lunwind-aarch64 > endif > > +# Additional ARCH settings for ARC > +ifeq ($(ARCH),arc) > + CFLAGS += -matomic > +endif > + > ifeq ($(NO_PERF_REGS),0) > $(call detected,CONFIG_PERF_REGS) > endif -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
