From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 94D48C3A5A3 for ; Tue, 27 Aug 2019 20:34:52 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 695D32077B for ; Tue, 27 Aug 2019 20:34:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 695D32077B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:58384 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2iB1-0004z3-Jf for qemu-devel@archiver.kernel.org; Tue, 27 Aug 2019 16:34:51 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:54438) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1i2iA2-00046h-IZ for qemu-devel@nongnu.org; Tue, 27 Aug 2019 16:33:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1i2iA1-0008Ng-Hd for qemu-devel@nongnu.org; Tue, 27 Aug 2019 16:33:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:39104) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1i2iA1-0008NX-CL for qemu-devel@nongnu.org; Tue, 27 Aug 2019 16:33:49 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id B7EE13084244; Tue, 27 Aug 2019 20:33:48 +0000 (UTC) Received: from localhost (ovpn-116-148.ams2.redhat.com [10.36.116.148]) by smtp.corp.redhat.com (Postfix) with ESMTP id D085560F82; Tue, 27 Aug 2019 20:33:45 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Date: Tue, 27 Aug 2019 21:33:40 +0100 Message-Id: <20190827203340.31195-2-stefanha@redhat.com> In-Reply-To: <20190827203340.31195-1-stefanha@redhat.com> References: <20190827203340.31195-1-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.40]); Tue, 27 Aug 2019 20:33:48 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PULL 1/1] trace: Clarify DTrace/SystemTap help message X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Stefan Hajnoczi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" From: Philippe Mathieu-Daud=C3=A9 Most tracing backends are implemented within QEMU, except the DTrace/SystemTap backends. One side effect is when running 'qemu -trace help', an incomplete list of trace events is displayed when using the DTrace/SystemTap backends. This is partly due to trace events registered as modules with trace_init(), and since the events are not used within QEMU, the linker optimize and remove the unused modules (which is OK in this particular case). Currently only the events compiled in trace-root.o and in the last trace.o member of libqemuutil.a are linked, resulting in an incomplete list of events. To avoid confusion, improve the help message, recommending to use the proper systemtap script to display the events list. Before: $ lm32-softmmu/qemu-system-lm32 -trace help 2>&1 | wc -l 70 After: $ lm32-softmmu/qemu-system-lm32 -trace help Run 'qemu-trace-stap list qemu-system-lm32' to print a list of names of trace points with the DTrace/SystemTap backends. $ qemu-trace-stap list qemu-system-lm32 | wc -l 1136 Signed-off-by: Philippe Mathieu-Daud=C3=A9 Message-id: 20190823142203.5210-1-philmd@redhat.com Message-Id: <20190823142203.5210-1-philmd@redhat.com> Signed-off-by: Stefan Hajnoczi --- trace/control.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/trace/control.c b/trace/control.c index 43fb7868db..d9cafc161b 100644 --- a/trace/control.c +++ b/trace/control.c @@ -165,6 +165,12 @@ void trace_list_events(void) while ((ev =3D trace_event_iter_next(&iter)) !=3D NULL) { fprintf(stderr, "%s\n", trace_event_get_name(ev)); } +#ifdef CONFIG_TRACE_DTRACE + fprintf(stderr, "This list of names of trace points may be incomplet= e " + "when using the DTrace/SystemTap backends.\n" + "Run 'qemu-trace-stap list %s' to print the full lis= t.\n", + error_get_progname()); +#endif } =20 static void do_trace_enable_events(const char *line_buf) --=20 2.21.0