From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:47461) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dUrfx-00025g-Gw for qemu-devel@nongnu.org; Tue, 11 Jul 2017 05:41:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dUrfu-0003Ba-BJ for qemu-devel@nongnu.org; Tue, 11 Jul 2017 05:41:49 -0400 Received: from mail-pg0-f51.google.com ([74.125.83.51]:34918) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dUrfu-0003At-5P for qemu-devel@nongnu.org; Tue, 11 Jul 2017 05:41:46 -0400 Received: by mail-pg0-f51.google.com with SMTP id j186so63871987pge.2 for ; Tue, 11 Jul 2017 02:41:43 -0700 (PDT) References: <8b8c84aa-16c0-2bac-3b8a-9be595682356@linux.vnet.ibm.com> From: Xie Changlong Message-ID: <2f6d682c-68af-b689-701b-b7b05a598d7a@gmail.com> Date: Tue, 11 Jul 2017 17:39:54 +0800 MIME-Version: 1.0 In-Reply-To: <8b8c84aa-16c0-2bac-3b8a-9be595682356@linux.vnet.ibm.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Subject: Re: [Qemu-devel] About the trace framework List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Wang Dong , qemu-devel@nongnu.org Cc: stefanha@redhat.com 在 7/11/2017 9:33 AM, Wang Dong 写道: > > > On 07/10/2017 01:24 PM, Xie Changlong wrote: >> 在 7/9/2017 5:57 PM, Wang Dong 写道: >>> Hi, >>> >>> I am new to QEMU. But I got some problem so that I want to figure it >>> out. >>> >>> So I try to debug qemu to see what happened. >>> >>> And I found trace framework. I think this will help me understand the >>> point. >>> >>> So I compiled qemu with option: >>> >>> ## *--enable-trace-backends=simple* >>> >>> And did as the docs/tracing.txt tell. But when I execute the example >>> command in it, nothing just happens. >>> >>> *./scripts/simpletrace.py trace-events-all trace-xxxxxx(my trace file >>> produced by qemu) >>> I am not sure what happened. Just ask this. >>> Any clue will be appreciated. Thanks in advance. >>> * >>> >> >> Did you set *trace-event*? I've encountered this issue in the past :) >> (qemu) help trace-event >> trace-event name on|off -- changes status of a specific trace event >> (qemu) info trace-events > yes, I set it. I just did as the docs told. If this does not work or > misses something, it should be corrected I think. > > Have you also tried out the examples in docs? how did you do that? I Yes, just follow the docs. No something special. > think I misses some. Could you tell more about > it? Thanks. You should confirm the *trace-event*s you set are really triggered by qemu. Use gdb breakpoint to verify it is a good choice. > -- Thanks -Xie