From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
Subject: Re: [PATCH v4 06/24] ethdev: enable hotplug on
	multi-process
Date: Tue, 26 Jun 2018 14:45:59 +0100
Message-ID: <53fe3a3e-ae37-0765-f83d-c88a279028a1@intel.com>
References: <20180607123849.14439-1-qi.z.zhang@intel.com>
 <20180626070832.3055-1-qi.z.zhang@intel.com>
 <20180626070832.3055-7-qi.z.zhang@intel.com>
 <969f0cb7-4186-d05c-442f-6341f1c44e93@intel.com>
 <039ED4275CED7440929022BC67E706115323E71A@SHSMSX103.ccr.corp.intel.com>
 <30b1c93c-1d7c-07d9-d41a-76e84f63d6a1@intel.com>
 <039ED4275CED7440929022BC67E706115323E7A5@SHSMSX103.ccr.corp.intel.com>
 <365fd549-14c6-ae72-84be-3ec7389eaa84@intel.com>
 <039ED4275CED7440929022BC67E706115323E7E2@SHSMSX103.ccr.corp.intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Cc: "Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
 "dev@dpdk.org" <dev@dpdk.org>, "Richardson, Bruce"
 <bruce.richardson@intel.com>, "Yigit, Ferruh" <ferruh.yigit@intel.com>,
 "Shelton, Benjamin H" <benjamin.h.shelton@intel.com>,
 "Vangati, Narender" <narender.vangati@intel.com>
To: "Zhang, Qi Z" <qi.z.zhang@intel.com>,
 "thomas@monjalon.net" <thomas@monjalon.net>
Return-path: <dev-bounces@dpdk.org>
Received: from mga03.intel.com (mga03.intel.com [134.134.136.65])
 by dpdk.org (Postfix) with ESMTP id 6B1451B60A
 for <dev@dpdk.org>; Tue, 26 Jun 2018 15:46:14 +0200 (CEST)
In-Reply-To: <039ED4275CED7440929022BC67E706115323E7E2@SHSMSX103.ccr.corp.intel.com>
Content-Language: en-US
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On 26-Jun-18 2:25 PM, Zhang, Qi Z wrote:
> 
> 
>> -----Original Message-----
>> From: Burakov, Anatoly
>> Sent: Tuesday, June 26, 2018 9:21 PM
>> To: Zhang, Qi Z <qi.z.zhang@intel.com>; thomas@monjalon.net
>> Cc: Ananyev, Konstantin <konstantin.ananyev@intel.com>; dev@dpdk.org;
>> Richardson, Bruce <bruce.richardson@intel.com>; Yigit, Ferruh
>> <ferruh.yigit@intel.com>; Shelton, Benjamin H
>> <benjamin.h.shelton@intel.com>; Vangati, Narender
>> <narender.vangati@intel.com>
>> Subject: Re: [PATCH v4 06/24] ethdev: enable hotplug on multi-process
>>
>> On 26-Jun-18 1:58 PM, Zhang, Qi Z wrote:
>>>
>>> my understand is peer is identified by a string (or filename) what I
>>> mean is clone the content of the buffer that peer point to , So I
>>> don't need to worry if the original peer be used to point to some
>>> other data
>>>
>>
>> As far as the application is concerned, peer is an opaque pointer, and should
>> be treated as such. Peeking behind a void pointer that is not designed for this
>> purpose is not a good idea, even if technically you know what's in there.
> 
> We can expose a clone interface, like MP_PEER_CLONE, so we don't need to know what's inside, just need to know that it can be used on another thread?
> 

Well, that can probably work. Feels like a hacky workaround though.

Another way to do the same thing would be to store peer information 
right in the message, as opposed to providing it separately. Still a 
hack though, and will require far more changes, but it could be a better 
solution as (if done right) it would allow identifying which reply came 
from which peer.

Of course, an even better approach would be to devise some kind of 
addressing scheme (uuid?), so that peer addresses are no longer opaque 
pointers but rather are valid data types.

Thoughts?

-- 
Thanks,
Anatoly