From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752859Ab2FEP3w (ORCPT ); Tue, 5 Jun 2012 11:29:52 -0400 Received: from mail.openrapids.net ([64.15.138.104]:47502 "EHLO blackscsi.openrapids.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752453Ab2FEP3v (ORCPT ); Tue, 5 Jun 2012 11:29:51 -0400 Date: Tue, 5 Jun 2012 11:29:47 -0400 From: Mathieu Desnoyers To: yoshihiro.yunomae.ez@hitachi.com Cc: linux-kernel@vger.kernel.org, Masami Hiramatsu , Steven Rostedt , Peter Zijlstra , Ingo Molnar Subject: ivring driver Message-ID: <20120605152947.GA21787@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Editor: vi X-Info: http://www.efficios.com User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Yoshihiro, I stumbled on your post on ivring (https://lkml.org/lkml/2012/6/5/143) for buffering trace data from guest to host. I notice that it would be very interesting to see a comparison of its performance against: - ftrace ring buffer - perf ring buffer - lttng 2.0 ring buffer - lttng-ust 2.0 (user-space tracing) ring buffer Comparing only with network-related mechanisms does not seem to provide a complete picture of where it stands wrt other ring buffers out there. One of the metric we have used in the past is the number of nanoseconds it takes to write a single event, based on a test that writes lots of events into various buffer sizes, into flight recorder mode buffers (which overwrites oldest information on buffer full condition, with data collection to disk disabled, to remove I/O from the picture -- I/O can then be performed in "snapshot" mode, after some error condition is detected). Best regards, Mathieu -- Mathieu Desnoyers Operating System Efficiency R&D Consultant EfficiOS Inc. http://www.efficios.com