From patchwork Thu Jul 23 13:29:01 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: 11681019 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2851613B1 for ; Thu, 23 Jul 2020 13:29:51 +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 F295220709 for ; Thu, 23 Jul 2020 13:29:50 +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="bqcbjWxw" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F295220709 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+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:44178 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jybIE-0003hn-6A for patchwork-qemu-devel@patchwork.kernel.org; Thu, 23 Jul 2020 09:29:50 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53522) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jybHl-0003DA-V4 for qemu-devel@nongnu.org; Thu, 23 Jul 2020 09:29:21 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:53464 helo=us-smtp-delivery-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 1jybHk-0005Ou-8q for qemu-devel@nongnu.org; Thu, 23 Jul 2020 09:29:21 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1595510959; 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=7LHWROqjZnKMbclNUPrma6/FcR/4VBkWfKYmDvJlMZo=; b=bqcbjWxwK4P7pYKlsP4ohRhq1+uZgsL1QGq4cNK5Z+WSeh/R/fbqhT7S9unQGCFdXtckNW xUpIvtKAKO1uAYI6yNnP15fNOq19JkpKdfLWYLAlyeL3uM3Qf3MCBUC5rcnR8nyz7diMAE rCML3YYFuzXv9PISUJ1/18PkSpnWwUA= 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-223-ZC9nhLYBPXqjiCFlVDF7bw-1; Thu, 23 Jul 2020 09:29:17 -0400 X-MC-Unique: ZC9nhLYBPXqjiCFlVDF7bw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 30C45100CCD2; Thu, 23 Jul 2020 13:29:16 +0000 (UTC) Received: from turbo.com (ovpn-113-141.ams2.redhat.com [10.36.113.141]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0A71E5D9D3; Thu, 23 Jul 2020 13:29:05 +0000 (UTC) From: Christophe de Dinechin To: qemu-devel@nongnu.org Subject: [PATCH v4 0/2] trace: Add a trace backend for the recorder library Date: Thu, 23 Jul 2020 15:29:01 +0200 Message-Id: <20200723132903.1980743-1-dinechin@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Received-SPF: pass client-ip=207.211.31.81; envelope-from=dinechin@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/23 02:26:42 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=ham autolearn_force=no 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: Michael Tokarev , Markus Armbruster , "Dr. David Alan Gilbert" , Stefan Hajnoczi , Christophe de Dinechin , Laurent Vivier Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.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. Changes in v4: * Rebased on current master * Fix GPL v2-only license * Remove confusing #ifdef around #include "trace/recorder.h" * Added myself as a reviewer for trace subsystem 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 MAINTAINERS | 1 + configure | 14 ++++++++ hmp-commands.hx | 23 +++++++++++- monitor/misc.c | 25 +++++++++++++ scripts/tracetool/backend/recorder.py | 52 +++++++++++++++++++++++++++ trace/Makefile.objs | 1 + trace/control.c | 5 +++ trace/recorder.c | 27 ++++++++++++++ trace/recorder.h | 32 +++++++++++++++++ util/module.c | 6 ++++ util/qemu-thread-common.h | 7 ++++ 11 files changed, 192 insertions(+), 1 deletion(-) create mode 100644 scripts/tracetool/backend/recorder.py create mode 100644 trace/recorder.c create mode 100644 trace/recorder.h