From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752824AbbJQOT0 (ORCPT ); Sat, 17 Oct 2015 10:19:26 -0400 Received: from smtprelay4.synopsys.com ([198.182.47.9]:54133 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752485AbbJQOTX convert rfc822-to-8bit (ORCPT ); Sat, 17 Oct 2015 10:19:23 -0400 From: Vineet Gupta To: Alexey Brodkin CC: Peter Zijlstra , Aabid Rushdi , lkml , "linux-perf-users@vger.kernel.org" , Darren Hart Subject: Re: [RFC] perf: fix building for ARCv1 Thread-Topic: [RFC] perf: fix building for ARCv1 Thread-Index: AQHRCODGqUIZ06l560WdnGKbYbcPAw== Date: Sat, 17 Oct 2015 14:19:19 +0000 Message-ID: References: <1445088959-3058-1-git-send-email-abrodkin@synopsys.com> Accept-Language: en-US, en-IN Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.12.239.235] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 > Cc: Peter Zijlstra > Cc: Arnaldo Carvalho de Melo > Signed-off-by: Alexey Brodkin > --- > 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