From: "Tan, Jianfeng" <jianfeng.tan@intel.com>
To: "Burakov, Anatoly" <anatoly.burakov@intel.com>,
"Ananyev, Konstantin" <konstantin.ananyev@intel.com>,
"dev@dpdk.org" <dev@dpdk.org>
Cc: "Richardson, Bruce" <bruce.richardson@intel.com>,
"thomas@monjalon.net" <thomas@monjalon.net>
Subject: Re: [dpdk-dev] [PATCH v3 2/3] eal: add synchronous multi-process communication
Date: Fri, 26 Jan 2018 01:10:34 +0800 [thread overview]
Message-ID: <3178bc08-02d4-9020-853f-a8a71f39bb50@intel.com> (raw)
In-Reply-To: <02b00727-e8cc-2041-f8b8-503f75f008f3@intel.com>
On 1/26/2018 12:22 AM, Burakov, Anatoly wrote:
> On 25-Jan-18 3:03 PM, Ananyev, Konstantin wrote:
>>
>>
>>> -----Original Message-----
>>> From: Burakov, Anatoly
>>> Sent: Thursday, January 25, 2018 1:10 PM
>>> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Tan,
>>> Jianfeng <jianfeng.tan@intel.com>; dev@dpdk.org
>>> Cc: Richardson, Bruce <bruce.richardson@intel.com>; thomas@monjalon.net
>>> Subject: Re: [dpdk-dev] [PATCH v3 2/3] eal: add synchronous
>>> multi-process communication
>>>
>>> On 25-Jan-18 1:05 PM, Burakov, Anatoly wrote:
>>>> On 25-Jan-18 1:00 PM, Ananyev, Konstantin wrote:
>>>>>
>>>>>
>>>>>> -----Original Message-----
>>>>>> From: Burakov, Anatoly
>>>>>> Sent: Thursday, January 25, 2018 12:26 PM
>>>>>> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; Tan,
>>>>>> Jianfeng
>>>>>> <jianfeng.tan@intel.com>; dev@dpdk.org
>>>>>> Cc: Richardson, Bruce <bruce.richardson@intel.com>;
>>>>>> thomas@monjalon.net
>>>>>> Subject: Re: [PATCH v3 2/3] eal: add synchronous multi-process
>>>>>> communication
>>>>>>
>>>>>> On 25-Jan-18 12:19 PM, Ananyev, Konstantin wrote:
>>>>>>>
>>>>>>>
>>>>>>>> -----Original Message-----
>>>>>>>> From: Burakov, Anatoly
>>>>>>>> Sent: Thursday, January 25, 2018 12:00 PM
>>>>>>>> To: Tan, Jianfeng <jianfeng.tan@intel.com>; dev@dpdk.org
>>>>>>>> Cc: Richardson, Bruce <bruce.richardson@intel.com>; Ananyev,
>>>>>>>> Konstantin <konstantin.ananyev@intel.com>; thomas@monjalon.net
>>>>>>>> Subject: Re: [PATCH v3 2/3] eal: add synchronous multi-process
>>>>>>>> communication
>>>>>>>>
>>>>>>>> On the overall patch,
>>>>>>>>
>>>>>>>> Reviewed-by: Anatoly Burakov <anatoly.burakov@intel.com>
>>>>>>>>
>>>>>>>> For request(), returning number of replies received actually makes
>>>>>>>> sense, because now we get use the value to read our replies, if we
>>>>>>>> were
>>>>>>>> a primary process sending messages to secondary processes.
>>>>>>>
>>>>>>> Yes, I also think it is good to return number of sends.
>>>>>>> Then caller can compare number of sended requests with number of
>>>>>>> received replies and decide should it be considered a failure or
>>>>>>> no.
>>>>>>>
>>>>>>
>>>>>> Well, OK, that might make sense. However, i think it would've be
>>>>>> of more
>>>>>> value to make the API consistent (0/-1 on success/failure) and put
>>>>>> number of sent messages into the reply, like number of received.
>>>>>> I.e.
>>>>>> something like
>>>>>>
>>>>>> struct reply {
>>>>>> int nb_sent;
>>>>>> int nb_received;
>>>>>> };
>>>>>>
>>>>>> We do it for the latter already, so why not the former?
>>>>>
>>>>> The question is what treat as success/failure?
>>>>> Let say we sent 2 requests (of 3 possible), got back 1 response...
>>>>> Should we consider it as success or failure?
>>>>>
>>>>
>>>> I think "failure" is "something went wrong", not "secondary processes
>>>> didn't respond". For example, invalid parameters, or our socket
>>>> suddenly
>>>> being closed, or some other error that prevents us from sending
>>>> requests
>>>> to secondaries.
>>>>
>>>> As far as i can tell from the code, there's no way to know if the
>>>> secondary process is running other than by attempting to connect to
>>>> it,
>>>> and get a response. So, failed connection should not be a failure
>>>> condition, because we can't know if we *can* connect to the process
>>>> until we do. Process may have ended, but socket files will still be
>>>> around, and there's nothing we can do about that. So i wouldn't
>>>> consider
>>>> inability to send a message a failure condition.
>>>>
>>>
>>> Just to clarify - i'm suggesting leaving this decision up to the user.
>>> If a user expects there to be "n" processes running, but only "m"
>>> responses were received, he could treat it as error. Another user might
>>> simply send periodical updates/polls to secondaries, for whatever
>>> reason
>>> (say, stats display), and won't really care if one of them just
>>> died, so
>>> there's no error for that user.
>>>
>>> However, all of this has nothing to do with API. If we're able to send
>>> messages - it's not a failure. If we can't - it is. That's the part API
>>> should be concerned about, and that's what the return value should
>>> indicate, IMO.
>>
>> Ok so to clarify, you are suggesting:
>> we have N peers - if send_msg() returns success for all N - return
>> success
>> (no matter did we get a reply or not)
>> Otherwise return a failure.
>> ?
>> Konstantin
>
> More along the lines of, return -1 if and only if something went
> wrong. That might be invalid parameters, or that might be an error
> with our own socket,
To check if the error is caused by our own socket, we check the errno
after sendmsg?
Like for remote socket errors, we check:
- ECONNRESET
- ECONNREFUSED
- ENOBUFS
Right?
Thanks,
Jianfeng
> or something else to that effect. In all other cases, return 0 (that
> includes cases where we sent N messages but M replies where N != M).
> So, in other words, return 0 if we *could have succeeded* if nothing
> went wrong on the other side, and only return -1 if something went
> wrong on our side.
>
>>
>>
>>>
>>> --
>>> Thanks,
>>> Anatoly
>
>
next prev parent reply other threads:[~2018-01-25 17:10 UTC|newest]
Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-30 18:44 [dpdk-dev] [PATCH 0/3] generic channel for " Jianfeng Tan
2017-11-30 18:44 ` [dpdk-dev] [PATCH 1/3] eal: add " Jianfeng Tan
2017-12-11 11:04 ` Burakov, Anatoly
2017-12-11 16:43 ` Ananyev, Konstantin
2017-11-30 18:44 ` [dpdk-dev] [PATCH 2/3] eal: add synchronous " Jianfeng Tan
2017-12-11 11:39 ` Burakov, Anatoly
2017-12-11 16:49 ` Ananyev, Konstantin
2017-11-30 18:44 ` [dpdk-dev] [PATCH 3/3] vfio: use the generic multi-process channel Jianfeng Tan
2017-12-11 12:01 ` Burakov, Anatoly
2017-12-11 9:59 ` [dpdk-dev] [PATCH 0/3] generic channel for multi-process communication Burakov, Anatoly
2017-12-12 7:34 ` Tan, Jianfeng
2017-12-12 16:18 ` Burakov, Anatoly
2018-01-11 4:07 ` [dpdk-dev] [PATCH v2 0/4] " Jianfeng Tan
2018-01-11 4:07 ` [dpdk-dev] [PATCH v2 1/4] eal: add " Jianfeng Tan
2018-01-13 12:57 ` Burakov, Anatoly
2018-01-15 19:52 ` Ananyev, Konstantin
2018-01-11 4:07 ` [dpdk-dev] [PATCH v2 2/4] eal: add and del secondary processes in the primary Jianfeng Tan
2018-01-13 13:11 ` Burakov, Anatoly
2018-01-15 21:45 ` Ananyev, Konstantin
2018-01-11 4:07 ` [dpdk-dev] [PATCH v2 3/4] eal: add synchronous multi-process communication Jianfeng Tan
2018-01-13 13:41 ` Burakov, Anatoly
2018-01-16 0:00 ` Ananyev, Konstantin
2018-01-16 8:10 ` Tan, Jianfeng
2018-01-16 11:12 ` Ananyev, Konstantin
2018-01-16 16:47 ` Tan, Jianfeng
2018-01-17 10:50 ` Ananyev, Konstantin
2018-01-17 13:09 ` Tan, Jianfeng
2018-01-17 13:15 ` Tan, Jianfeng
2018-01-17 17:20 ` Ananyev, Konstantin
2018-01-11 4:07 ` [dpdk-dev] [PATCH v2 4/4] vfio: use the generic multi-process channel Jianfeng Tan
2018-01-13 14:03 ` Burakov, Anatoly
2018-03-04 14:57 ` [dpdk-dev] [PATCH v5] vfio: change to use " Jianfeng Tan
2018-03-14 13:27 ` Burakov, Anatoly
2018-03-19 6:53 ` Tan, Jianfeng
2018-03-20 10:33 ` Burakov, Anatoly
2018-03-20 10:56 ` Burakov, Anatoly
2018-03-20 8:50 ` [dpdk-dev] [PATCH v6] " Jianfeng Tan
2018-04-05 14:26 ` Tan, Jianfeng
2018-04-05 14:39 ` Burakov, Anatoly
2018-04-12 23:27 ` Thomas Monjalon
2018-04-12 15:26 ` Burakov, Anatoly
2018-04-15 15:06 ` [dpdk-dev] [PATCH v7] " Jianfeng Tan
2018-04-15 15:10 ` Tan, Jianfeng
2018-04-17 23:04 ` Thomas Monjalon
2018-01-25 4:16 ` [dpdk-dev] [PATCH v3 0/3] generic channel for multi-process communication Jianfeng Tan
2018-01-25 4:16 ` [dpdk-dev] [PATCH v3 1/3] eal: add " Jianfeng Tan
2018-01-25 10:41 ` Thomas Monjalon
2018-01-25 11:27 ` Burakov, Anatoly
2018-01-25 11:34 ` Thomas Monjalon
2018-01-25 12:21 ` Ananyev, Konstantin
2018-01-25 4:16 ` [dpdk-dev] [PATCH v3 2/3] eal: add synchronous " Jianfeng Tan
2018-01-25 12:00 ` Burakov, Anatoly
2018-01-25 12:19 ` Ananyev, Konstantin
2018-01-25 12:25 ` Burakov, Anatoly
2018-01-25 13:00 ` Ananyev, Konstantin
2018-01-25 13:05 ` Burakov, Anatoly
2018-01-25 13:10 ` Burakov, Anatoly
2018-01-25 15:03 ` Ananyev, Konstantin
2018-01-25 16:22 ` Burakov, Anatoly
2018-01-25 17:10 ` Tan, Jianfeng [this message]
2018-01-25 18:02 ` Burakov, Anatoly
2018-01-25 12:19 ` Burakov, Anatoly
2018-01-25 12:22 ` Ananyev, Konstantin
2018-01-25 4:16 ` [dpdk-dev] [PATCH v3 3/3] vfio: use the generic multi-process channel Jianfeng Tan
2018-01-25 10:47 ` Thomas Monjalon
2018-01-25 10:52 ` Burakov, Anatoly
2018-01-25 10:57 ` Thomas Monjalon
2018-01-25 12:15 ` Burakov, Anatoly
2018-01-25 19:14 ` [dpdk-dev] [PATCH v4 0/2] generic channel for multi-process communication Jianfeng Tan
2018-01-25 19:14 ` [dpdk-dev] [PATCH v4 1/2] eal: add synchronous " Jianfeng Tan
2018-01-25 19:14 ` [dpdk-dev] [PATCH v4 2/2] vfio: use the generic multi-process channel Jianfeng Tan
2018-01-25 19:15 ` [dpdk-dev] [PATCH v4 0/2] generic channel for multi-process communication Tan, Jianfeng
2018-01-25 19:21 ` [dpdk-dev] [PATCH v5 " Jianfeng Tan
2018-01-25 19:21 ` [dpdk-dev] [PATCH v5 1/2] eal: add " Jianfeng Tan
2018-01-25 19:21 ` [dpdk-dev] [PATCH v5 2/2] eal: add synchronous " Jianfeng Tan
2018-01-25 21:23 ` [dpdk-dev] [PATCH v5 0/2] generic channel for " Thomas Monjalon
2018-01-26 3:41 ` [dpdk-dev] [PATCH v6 " Jianfeng Tan
2018-01-26 3:41 ` [dpdk-dev] [PATCH v6 1/2] eal: add " Jianfeng Tan
2018-01-26 10:25 ` Burakov, Anatoly
2018-01-29 6:37 ` Tan, Jianfeng
2018-01-29 9:37 ` Burakov, Anatoly
2018-01-26 3:41 ` [dpdk-dev] [PATCH v6 2/2] eal: add synchronous " Jianfeng Tan
2018-01-26 10:31 ` Burakov, Anatoly
2018-01-29 23:52 ` [dpdk-dev] [PATCH v6 0/2] generic channel for " Thomas Monjalon
2018-01-30 6:58 ` [dpdk-dev] [PATCH v7 " Jianfeng Tan
2018-01-30 6:58 ` [dpdk-dev] [PATCH v7 1/2] eal: add " Jianfeng Tan
2018-01-30 6:58 ` [dpdk-dev] [PATCH v7 2/2] eal: add synchronous " Jianfeng Tan
2018-01-30 14:46 ` [dpdk-dev] [PATCH v7 0/2] generic channel for " Thomas Monjalon
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=3178bc08-02d4-9020-853f-a8a71f39bb50@intel.com \
--to=jianfeng.tan@intel.com \
--cc=anatoly.burakov@intel.com \
--cc=bruce.richardson@intel.com \
--cc=dev@dpdk.org \
--cc=konstantin.ananyev@intel.com \
--cc=thomas@monjalon.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).