Date: Mon, 11 May 2015 11:30:10 +0200
From: Ingo Molnar <mingo@kernel.org>
To: He Kuang <hekuang@huawei.com>
Cc: masami.hiramatsu.pt@hitachi.com, a.p.zijlstra@chello.nl, acme@kernel.org,
        jolsa@kernel.org, mingo@redhat.com, wangnan0@huawei.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3 3/3] perf probe: Show better error message when failed
 to find variable
Message-ID: <20150511093010.GA31869@gmail.com>
References: <1431336304-16863-1-git-send-email-hekuang@huawei.com>
 <1431336304-16863-3-git-send-email-hekuang@huawei.com>
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* He Kuang <hekuang@huawei.com> 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.

>    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
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