From patchwork Thu Dec 8 22:48:07 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Llu=C3=ADs_Vilanova?= X-Patchwork-Id: 130251 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [140.186.70.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 80EF01007D1 for ; Fri, 9 Dec 2011 09:48:26 +1100 (EST) Received: from localhost ([::1]:42321 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RYmlL-0002RZ-QO for incoming@patchwork.ozlabs.org; Thu, 08 Dec 2011 17:48:23 -0500 Received: from eggs.gnu.org ([140.186.70.92]:56901) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RYmlF-0002Ng-Ah for qemu-devel@nongnu.org; Thu, 08 Dec 2011 17:48:18 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RYmlE-0007yg-79 for qemu-devel@nongnu.org; Thu, 08 Dec 2011 17:48:17 -0500 Received: from gw.ac.upc.edu ([147.83.30.3]:42597) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RYmlD-0007yb-Oj for qemu-devel@nongnu.org; Thu, 08 Dec 2011 17:48:16 -0500 Received: from localhost (unknown [84.88.53.92]) by gw.ac.upc.edu (Postfix) with ESMTP id 9F72C6B02C9 for ; Thu, 8 Dec 2011 23:48:14 +0100 (CET) To: qemu-devel@nongnu.org From: =?utf-8?b?TGx1w61z?= Vilanova Date: Thu, 08 Dec 2011 23:48:07 +0100 Message-ID: <20111208224807.21668.94467.stgit@ginnungagap.bsc.es> In-Reply-To: <20111208224750.21668.26153.stgit@ginnungagap.bsc.es> References: <20111208224750.21668.26153.stgit@ginnungagap.bsc.es> User-Agent: StGit/0.15 MIME-Version: 1.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 147.83.30.3 Subject: [Qemu-devel] [PATCH 01/10] trace: [doc] Document event properties on a separate section X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Signed-off-by: Lluís Vilanova --- docs/tracing.txt | 22 ++++++++++++++++------ 1 files changed, 16 insertions(+), 6 deletions(-) diff --git a/docs/tracing.txt b/docs/tracing.txt index ea29f2c..853cbf8 100644 --- a/docs/tracing.txt +++ b/docs/tracing.txt @@ -98,12 +98,6 @@ respectively. This ensures portability between 32- and 64-bit platforms. 4. Name trace events after their function. If there are multiple trace events in one function, append a unique distinguisher at the end of the name. -5. If specific trace events are going to be called a huge number of times, this - might have a noticeable performance impact even when the trace events are - programmatically disabled. In this case you should declare the trace event - with the "disable" property, which will effectively disable it at compile - time (using the "nop" backend). - == Generic interface and monitor commands == You can programmatically query and control the dynamic state of trace events @@ -234,3 +228,19 @@ probes: --target-type system \ --target-arch x86_64 \ qemu.stp + +== Trace event properties == + +Each event in the "trace-events" file can be prefixed with a space-separated +list of zero or more of the following event properties. + +=== "disable" === + +If a specific trace event is going to be invoked a huge number of times, this +might have a noticeable performance impact even when the event is +programmatically disabled. + +In this case you should declare such event with the "disable" property. This +will effectively disable the event at compile time (by using the "nop" backend), +thus having no performance impact at all on regular builds (i.e., unless you +edit the "trace-events" file).