From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753262AbdDLLwn (ORCPT ); Wed, 12 Apr 2017 07:52:43 -0400 Received: from us01smtprelay-2.synopsys.com ([198.182.60.111]:38371 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753267AbdDLLwk (ORCPT ); Wed, 12 Apr 2017 07:52:40 -0400 From: Alexey Brodkin To: "jolsa@redhat.com" CC: "jolsa@kernel.org" , "acme@redhat.com" , "a.p.zijlstra@chello.nl" , "linux-kernel@vger.kernel.org" , "linux-snps-arc@lists.infradead.org" , "davidcc@google.com" Subject: Re: perf jvmti: unconditionally links against -lelf Thread-Topic: perf jvmti: unconditionally links against -lelf Thread-Index: AQHSs3NUYBsj93KHk0qNlBBHzU/dYqHBZDiAgAAZ54A= Date: Wed, 12 Apr 2017 11:52:36 +0000 Message-ID: <1491997955.4510.42.camel@synopsys.com> References: <1491991105.4510.25.camel@synopsys.com> <20170412101953.GB14409@krava> In-Reply-To: <20170412101953.GB14409@krava> Accept-Language: en-US, ru-RU Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.225.15.124] Content-Type: text/plain; charset="utf-8" Content-ID: <93720FED53A9754E9A4AD9D19113C523@internal.synopsys.com> MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id v3CBqmYH003439 Hi Jiri, On Wed, 2017-04-12 at 12:19 +0200, Jiri Olsa wrote: > On Wed, Apr 12, 2017 at 09:58:26AM +0000, Alexey Brodkin wrote: > > > > Hi Jiri, > > > > Just tried to cross-compile perf with pretty bare-minimal toolchain > > which has no libelf installed for the target (for the record I used > > SNPS ARC pre-built arc-2016.09 tools) like that: > > --------------->8------------ > > make NO_LIBELF=1 > > --------------->8------------ > > > > And got the following build failure: > > --------------->8------------ > >   LINK     libperf-jvmti.so > > .../2016.09-uclibc-archs/bin/../lib/gcc/arc-snps-linux-uclibc/6.2.1/../../../../arc-snps-linux-uclibc/bin/ld: cannot find -lelf > > --------------->8------------ > > > > First I was surprised because I intentionally disabled usage of libelf > > but after some grepping figured out jvmti is linked against libelf > > regardless any settings, see: > > --------------->8------------ > > $(OUTPUT)$(LIBJVMTI): $(LIBJVMTI_IN) > >        $(QUIET_LINK)$(CC) -shared -Wl,-soname -Wl,$(LIBJVMTI) -o $@ $< -lelf -lrt > > endif > > --------------->8------------ > > > > This comes from commit d4dfdf00d43e ("perf jvmti: Plug compilation into perf build"). > > > > I'm not really sure what could be the best solution to the problem I see. > > If libelf is a real must for jvmti then probably we may force set NO_JVMTI=1 > > if NO_LIBELF=1 is passed on the command line. > > > > At least the following builds perf for me without issues: > > --------------->8------------ > > make NO_LIBELF=1 NO_JVMTI=1 > > --------------->8------------ > > hi, > incidently, David just posted patch for this ;-) So good to know somebody has already fixed my problem :) Thanks for letting me know! -Alexey