From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751172AbdFADfn (ORCPT ); Wed, 31 May 2017 23:35:43 -0400 Received: from mga02.intel.com ([134.134.136.20]:63974 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751052AbdFADfm (ORCPT ); Wed, 31 May 2017 23:35:42 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.39,277,1493708400"; d="scan'208";a="109468364" Subject: Re: [PATCH v8 2/5] usb: early: add driver for xhci debug capability To: Steven Rostedt References: <1490083293-3792-1-git-send-email-baolu.lu@linux.intel.com> <1490083293-3792-3-git-send-email-baolu.lu@linux.intel.com> <592E3817.4030402@linux.intel.com> <20170531022439.54b93c69@vmware.local.home> Cc: Vlastimil Babka , Greg Kroah-Hartman , Ingo Molnar , Mathias Nyman , tglx@linutronix.de, peterz@infradead.org, linux-usb@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org From: Lu Baolu Message-ID: <592F8B87.70906@linux.intel.com> Date: Thu, 1 Jun 2017 11:35:35 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20170531022439.54b93c69@vmware.local.home> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 05/31/2017 02:24 PM, Steven Rostedt wrote: > On Wed, 31 May 2017 11:27:19 +0800 > Lu Baolu wrote: > > >>>> + >>>> +#define XDBC_TRACE >>>> +#ifdef XDBC_TRACE >>>> +#define xdbc_trace trace_printk >>> Did you forget to remove the #define XDBC_TRACE? >>> >>> Enabling this driver brings the "trace_printk() being used. >>> Allocating extra memory. This means that this is a DEBUG kernel and >>> it is unsafe for production use." message in 4.12-rcX dmesg. >> This feature is only for a DEBUG kernel, should not be enabled for >> any production kernel. This was the reason I enabled trace_printk() >> by default. > Yes, it is perfectly fine to use trace_printk() for debug only configs. > But if if you have it there and it is helpful to debug something that > happens in a production system, you may want to look into creating a > real tracepoint for the locations. Yes. Good suggestion. I will try this. Thank you! Best regards, Lu Baolu > > -- Steve > -- > To unsubscribe from this list: send the line "unsubscribe linux-usb" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >