From patchwork Mon Jul 6 17:02:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe de Dinechin X-Patchwork-Id: 278423 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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS autolearn=no 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 CA257C433E0 for ; Mon, 6 Jul 2020 17:08:56 +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 9179521582 for ; Mon, 6 Jul 2020 17:08:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="fS4ydFlF" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9179521582 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]:38862 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jsUbv-0008Mz-QY for qemu-devel@archiver.kernel.org; Mon, 06 Jul 2020 13:08:55 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:33516) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jsUWP-00047z-VX for qemu-devel@nongnu.org; Mon, 06 Jul 2020 13:03:14 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:41619 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jsUWO-0006ed-Bc for qemu-devel@nongnu.org; Mon, 06 Jul 2020 13:03:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594054991; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=apfggld3R7K2A3T1PK9XU7I7BAXDd4dvfqV923imVeM=; b=fS4ydFlFfEIqPJREDpLJQmMuHPzPW2W0prujzlbJbHWLWQExBFLSdwz3hrugLjM2XpeNlc q7Fdq9hOaQq4YxPKcW5OzGBwYLSkhdnR5fVn3aY2cqzItyzcgA0KezGXsqfkZcab45Ll3j qcsP0fCbw9MXYDWpkcpOv7xYTChZlQ4= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-56-EU33qf56OaCss9KtKEsG5w-1; Mon, 06 Jul 2020 13:03:09 -0400 X-MC-Unique: EU33qf56OaCss9KtKEsG5w-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id CA522461; Mon, 6 Jul 2020 17:03:08 +0000 (UTC) Received: from turbo.com (ovpn-114-213.ams2.redhat.com [10.36.114.213]) by smtp.corp.redhat.com (Postfix) with ESMTP id 285635BACD; Mon, 6 Jul 2020 17:02:57 +0000 (UTC) From: Christophe de Dinechin To: qemu-devel@nongnu.org Subject: [PATCH v3 0/2] trace: Add a trace backend for the recorder library Date: Mon, 6 Jul 2020 19:02:53 +0200 Message-Id: <20200706170255.1165105-1-dinechin@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dinechin@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=205.139.110.120; envelope-from=dinechin@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/06 01:22:37 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, URIBL_BLOCKED=0.001 autolearn=_AUTOLEARN X-Spam_action: no action 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: "Dr. David Alan Gilbert" , Michael Tokarev , Laurent Vivier , Stefan Hajnoczi , Markus Armbruster Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" The recorder library implements low-cost always-on tracing, with three usage models: 1. Flight recorder: Dump information on recent events in case of crash 2. Tracing: Individual traces can be enabled using environment variables 3. Real-time graphing / control, using the recorder_scope application This short series introduces a new "recorder" back-end which connects to the recorder. Traces using the recorder are intentionally "always on", because the recorder library is primarily designed to record information for later playback in case of crash, tracing being only a secondary capability. An example is given of how the recorder can also be used separately from generated traces. The example uses locking, which can make sense for both post-mortem and real-time graphing. Changes in v3: * Address coding style issues (C++ comments, wrong include, etc) * Fix args type for HMP command (for now, still a single command) * Add basic help for HMP command * Use pkg-config for recorder information. This requires recorder 1.0.10 or later. Later patches wil address larger topics that were discussed that would impact other tracing mechanisms, as well as GitHub / GitLab build tests. Christophe de Dinechin (2): trace: Add support for recorder back-end trace: Example of non-tracing recorder use configure | 14 ++++++++ hmp-commands.hx | 23 +++++++++++- monitor/misc.c | 27 ++++++++++++++ scripts/tracetool/backend/recorder.py | 52 +++++++++++++++++++++++++++ trace/Makefile.objs | 1 + trace/control.c | 7 ++++ trace/recorder.c | 25 +++++++++++++ trace/recorder.h | 32 +++++++++++++++++ util/module.c | 8 +++++ util/qemu-thread-common.h | 7 ++++ 10 files changed, 195 insertions(+), 1 deletion(-) create mode 100644 scripts/tracetool/backend/recorder.py create mode 100644 trace/recorder.c create mode 100644 trace/recorder.h -- 2.26.2