Subject: Re: [RFC 4/4] perf kvm: Fix output fields instead of 'trace' for perf
 kvm report on powerpc
To: Arnaldo Carvalho de Melo <acme@kernel.org>
References: <1456304865-15131-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com>
 <1456304865-15131-5-git-send-email-ravi.bangoria@linux.vnet.ibm.com>
 <20160302142556.GR3604@kernel.org> <56D70AE8.1080501@linux.vnet.ibm.com>
 <20160302162220.GS3604@kernel.org>
Cc: linux-kernel@vger.kernel.org, hemant@linux.vnet.ibm.com,
        naveen.n.rao@linux.vnet.ibm.com
From: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Message-ID: <56D79117.8040104@linux.vnet.ibm.com>
Date: Thu, 3 Mar 2016 06:49:19 +0530
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: <20160302162220.GS3604@kernel.org>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Content-Length: 1535
Lines: 46

Thanks acme,

On Wednesday 02 March 2016 09:52 PM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Mar 02, 2016 at 09:16:48PM +0530, Ravi Bangoria escreveu:
>> Thanks Arnaldo,
>>
>> Please find my comments.
>>
>> On Wednesday 02 March 2016 07:55 PM, Arnaldo Carvalho de Melo wrote:
>>> Em Wed, Feb 24, 2016 at 02:37:45PM +0530, Ravi Bangoria escreveu:
>>>>   		use_browser = 0;
>>>> +	if (!field_order &&
>>>> +	    is_perf_data_reorded_on_ppc(session->evlist) &&
>>>> +	    perf_guest_only())
>>>> +		field_order = "overhead,comm,dso,sym";
>>>> +
>>> Can you please do it as:
>>>
>>> __weak void arch__override_field_order(struct perf_evlist *evlist, const char **field_order)
>>> {
>>> }
>> So you mean like this - Just implement only weak function and move code into
>> it?
>> ie. No strong implementation at this point of time.
>>
>> Like,
>>
>> __weak void arch__override_field_order(struct perf_evlist *evlist, const
>> char **f_order)
>> {
>>      if (!field_order &&
>>          is_perf_data_reorded_on_ppc(session->evlist) &&
> Oh, I see, ugh, when running on x86_64 we wouldn't use this, so we need
> to have per arch default field orders, now I have to recall why is it
> that we need this per-arch field order :-\

Sorry, I'm little bit confused. We need arch specific functionality present
on all arch to make cross arch reporting possible.

for example, record perf.data on ppc and report on x86, we need
ppc specific function present in perf binary compiled on x86.

Please let me know if I understood it wrong.

Regads,
Ravi