From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 9D8F71A0024 for ; Tue, 29 Sep 2015 16:53:41 +1000 (AEST) Date: Tue, 29 Sep 2015 08:53:36 +0200 From: Jiri Olsa To: "Naveen N. Rao" Cc: Stephane Eranian , Arnaldo Carvalho de Melo , LKML , "mingo@redhat.com" , linuxppc-dev@lists.ozlabs.org, Sukadev Bhattiprolu Subject: Re: [PATCH] perf record: Limit --intr-regs to platforms supporting PERF_REGS Message-ID: <20150929065335.GE18363@krava.redhat.com> References: <1443096718-11926-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com> <20150924125703.GA11857@krava.redhat.com> <20150924164554.GA11493@naverao1-tp.in.ibm.com> <20150929053617.GA1060@naverao1-tp.in.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20150929053617.GA1060@naverao1-tp.in.ibm.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Sep 29, 2015 at 11:06:17AM +0530, Naveen N. Rao wrote: > On 2015/09/24 10:15PM, Naveen N Rao wrote: > > On 2015/09/24 08:32AM, Stephane Eranian wrote: > > > On Thu, Sep 24, 2015 at 5:57 AM, Jiri Olsa wrote: > > > > > > > > On Thu, Sep 24, 2015 at 05:41:58PM +0530, Naveen N. Rao wrote: > > > > > perf build currently fails on powerpc: > > > > > > > > > > LINK perf > > > > > libperf.a(libperf-in.o):(.toc+0x120): undefined reference to > > > > > `sample_reg_masks' > > > > > libperf.a(libperf-in.o):(.toc+0x130): undefined reference to > > > > > `sample_reg_masks' > > > > > collect2: error: ld returned 1 exit status > > > > > make[1]: *** [perf] Error 1 > > > > > make: *** [all] Error 2 > > > > > > > > > > This is due to parse-regs-options.c using sample_reg_masks, which is > > > > > defined only with CONFIG_PERF_REGS. > > > > > > > > > > In addition, perf record -I is only useful if the arch supports > > > > > PERF_REGS. Hence, let's expose -I conditionally. > > > > > > > > > > Signed-off-by: Naveen N. Rao > > > > > > > > hum, I wonder why we have sample_reg_masks defined as weak in util/perf_regs.c > > > > which is also built only via CONFIG_PERF_REGS > > > > > > > > I wonder we could get rid of the weak definition via attached patch, Stephane? > > > > > > > But the whole point of having it weak is to avoid this error scenario > > > on any arch without support > > > and avoid ugly #ifdef HAVE_ in generic files. > > > > > > if perf_regs.c is compiled on PPC, then why do we get the undefined? > > > > As Jiri Olsa pointed out, powerpc and many other architectures don't > > (yet) have support for perf regs. > > > > But, the larger reason to introduce #ifdef is so the user doesn't see > > options (s)he can't use on a specific architecture, along the same lines > > as builtin-probe.c > > Stephane, Arnaldo, > Suka has also posted a fix for this with a different approach [1]. Can > you please ack/pull one of these versions? Building perf is broken on > v4.3-rc due to this. I did not get any answer for additional comments I made to the patch (couldnt get marc.info working, sending the patch again) > > [1] http://article.gmane.org/gmane.linux.kernel/2046370 I dont have this last version, which seems to have other changes and patch in above link looks mangled, could you please repost it? thanks, jirka --- diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 142eeb341b29..19c8fd22fbe3 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1082,9 +1082,11 @@ struct option __record_options[] = { "sample transaction flags (special events only)"), OPT_BOOLEAN(0, "per-thread", &record.opts.target.per_thread, "use per-thread mmaps"), +#ifdef HAVE_PERF_REGS_SUPPORT OPT_CALLBACK_OPTARG('I', "intr-regs", &record.opts.sample_intr_regs, NULL, "any register", "sample selected machine registers on interrupt," " use -I ? to list register names", parse_regs), +#endif OPT_BOOLEAN(0, "running-time", &record.opts.running_time, "Record running/enabled time of read (:S) events"), OPT_CALLBACK('k', "clockid", &record.opts, diff --git a/tools/perf/util/Build b/tools/perf/util/Build index 4bc7a9ab45b1..93c6371405a3 100644 --- a/tools/perf/util/Build +++ b/tools/perf/util/Build @@ -104,7 +104,7 @@ libperf-$(CONFIG_LIBBABELTRACE) += data-convert-bt.o libperf-y += scripting-engines/ -libperf-$(CONFIG_PERF_REGS) += perf_regs.o +libperf-y += perf_regs.o libperf-$(CONFIG_ZLIB) += zlib.o libperf-$(CONFIG_LZMA) += lzma.o