Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752908AbbEKJpk (ORCPT ); Mon, 11 May 2015 05:45:40 -0400 Received: from szxga01-in.huawei.com ([58.251.152.64]:6608 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750973AbbEKJpj (ORCPT ); Mon, 11 May 2015 05:45:39 -0400 Subject: Re: [PATCH v3 3/3] perf probe: Show better error message when failed to find variable To: Ingo Molnar References: <1431336304-16863-1-git-send-email-hekuang@huawei.com> <1431336304-16863-3-git-send-email-hekuang@huawei.com> <20150511093010.GA31869@gmail.com> CC: , , , , , , From: He Kuang Message-ID: <555079CF.40701@huawei.com> Date: Mon, 11 May 2015 17:43:43 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Thunderbird/38.0 MIME-Version: 1.0 In-Reply-To: <20150511093010.GA31869@gmail.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.110.54.65] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1687 Lines: 49 Hi, Ingo On 2015/5/11 17:30, Ingo Molnar wrote: > * He Kuang wrote: > >> Indicate to check variable location range in error message when we got >> failed to find the variable. >> >> Before this patch: >> >> $ perf probe --add 'generic_perform_write+118 bytes' >> Failed to find the location of bytes at this address. >> Perhaps, it has been optimized out. >> Error: Failed to add events. >> >> After this patch: >> $ perf probe --add 'generic_perform_write+118 bytes' >> Failed to find the location of bytes at this address. > What does this sentence mean? I thought 'address' means 'location of > bytes'. So the address identifies the location and obviously we know > that. So this message wants to say something else. 'generic_perform_write' is a function name, while 'bytes' is a local variable in this function. Maybe the variable I chose make you confused. This maybe clear: Failed to find the location of 'bytes' at this address. >> Perhaps, it has been optimized out. >> Use -V with --range option to show variable location range. > This suggestion is useful. > >> Error: Failed to add events. > Thanks, > > Ingo > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/