Message-ID: <5551118F.7060101@hitachi.com>
Date: Tue, 12 May 2015 05:31:11 +0900
From: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Organization: Hitachi, Ltd., Japan
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To: Arnaldo Carvalho de Melo <acme@kernel.org>
CC: He Kuang <hekuang@huawei.com>, Ingo Molnar <mingo@kernel.org>,
        a.p.zijlstra@chello.nl, jolsa@kernel.org, mingo@redhat.com,
        wangnan0@huawei.com, linux-kernel@vger.kernel.org
Subject: Re: Re: Re: [PATCH v3 3/3] perf probe: Show better error message
 when failed to find variable
References: <1431336304-16863-1-git-send-email-hekuang@huawei.com> <1431336304-16863-3-git-send-email-hekuang@huawei.com> <20150511093010.GA31869@gmail.com> <555079CF.40701@huawei.com> <20150511095052.GA7441@gmail.com> <55508149.8040404@huawei.com> <55509A67.1040704@hitachi.com> <20150511133527.GB28183@kernel.org> <20150511134420.GC28183@kernel.org>
In-Reply-To: <20150511134420.GC28183@kernel.org>
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On 2015/05/11 22:44, Arnaldo Carvalho de Melo wrote:
> Em Mon, May 11, 2015 at 10:35:27AM -0300, Arnaldo Carvalho de Melo escreveu:
>> Em Mon, May 11, 2015 at 09:02:47PM +0900, Masami Hiramatsu escreveu:
>>> On 2015/05/11 19:15, He Kuang wrote:
>>>> On 2015/5/11 17:50, Ingo Molnar wrote:
>>>>> * He Kuang <hekuang@huawei.com> wrote:
>>>>>> On 2015/5/11 17:30, Ingo Molnar wrote:
>>>>>>>> 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.
>>>>> Yeah, absolutely! This highlights the importance of putting
>>>>> user-supplied symbols into quotes and such.
>>
>>>>> Maybe even write:
>>
>>>>>      Failed to find the location of the 'bytes' variable at this address.
>>  
>>> OK, He, could you also include this fix?
>>
>> I agree with the change, makes things clearer, will do the change
>> myself. If He has any objection to that, I can fix things up before
>> pushing it to Ingo,

Opps, I missed this...

> 
> So, this is the end result:
> 
> -       if (ret == -ENOENT || ret == -EINVAL)
> -               pr_err("Failed to find the location of %s at this address.\n"
> -                      " Perhaps, it has been optimized out.\n", pf->pvar->var);
> -       else if (ret == -ENOTSUP)
> +       if (ret == -ENOENT || ret == -EINVAL) {
> +               pr_err("Failed to find the location of the '%s' variable at this address.\n"
> +                      " Perhaps it has been optimized out.\n"
> +                      " Use -V with the --range option to show '%s' location range.\n",
> +                      pf->pvar->var, pf->pvar->var);
> +       } else if (ret == -ENOTSUP)

OK, I ack this change.

Thank you,


-- 
Masami HIRAMATSU
Linux Technology Research Center, System Productivity Research Dept.
Center for Technology Innovation - Systems Engineering
Hitachi, Ltd., Research & Development Group
E-mail: masami.hiramatsu.pt@hitachi.com
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