From: "Burakov, Anatoly" <anatoly.burakov@intel.com>
To: "Tan, Jianfeng" <jianfeng.tan@intel.com>, dev@dpdk.org
Cc: thomas@monjalon.net
Subject: Re: [dpdk-dev] [PATCH v3 3/5] bus/vdev: bus scan by multi-process channel
Date: Fri, 20 Apr 2018 16:39:59 +0100 [thread overview]
Message-ID: <b7f08ebe-2a90-f2a3-cb12-56f1b938fd80@intel.com> (raw)
In-Reply-To: <278a73fd-f877-6113-d47c-160c4adb24bb@intel.com>
On 20-Apr-18 4:32 PM, Tan, Jianfeng wrote:
>
>
> On 4/20/2018 11:19 PM, Burakov, Anatoly wrote:
>> On 20-Apr-18 3:28 PM, Tan, Jianfeng wrote:
>>>
>>>
>>> On 4/20/2018 4:41 PM, Burakov, Anatoly wrote:
>>>> On 19-Apr-18 5:50 PM, Jianfeng Tan wrote:
>>>>> To scan the vdevs in primary, we send request to primary process
>>>>> to obtain the names for vdevs.
>>>>>
>>>>> Only the name is shared from the primary. In probe(), the device
>>>>> driver is supposed to locate (or request more) the detail
>>>>> information from the primary.
>>>>>
>>>>> Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>
>>>>> Reviewed-by: Qi Zhang <qi.z.zhang@intel.com>
>>>>> ---
>>>>
>>>> <...>
>>>>
>>>>> +static int
>>>>> +vdev_action(const struct rte_mp_msg *mp_msg, const void *peer)
>>>>> +{
>>>>> + struct rte_vdev_device *dev;
>>>>> + struct rte_mp_msg mp_resp;
>>>>> + struct vdev_param *ou = (struct vdev_param *)&mp_resp.param;
>>>>> + const struct vdev_param *in = (const struct vdev_param
>>>>> *)mp_msg->param;
>>>>> + const char *devname;
>>>>> + int num;
>>>>> +
>>>>> + strcpy(mp_resp.name, "vdev");
>>>>> + mp_resp.len_param = sizeof(*ou);
>>>>> + mp_resp.num_fds = 0;
>>>>> +
>>>>> + switch (in->type) {
>>>>> + case VDEV_SCAN_REQ:
>>>>> + ou->type = VDEV_SCAN_ONE;
>>>>> + ou->num = 1;
>>>>> + num = 0;
>>>>> +
>>>>> + rte_spinlock_lock(&vdev_device_list_lock);
>>>>> + TAILQ_FOREACH(dev, &vdev_device_list, next) {
>>>>> + devname = rte_vdev_device_name(dev);
>>>>> + if (strlen(devname) == 0)
>>>>> + VDEV_LOG(INFO, "vdev with no name is not sent");
>>>>> + VDEV_LOG(INFO, "send vdev, %s", devname);
>>>>> + strncpy(ou->name, devname, RTE_DEV_NAME_MAX_LEN);
>>>>
>>>> Probably better use strlcpy as it always null-terminates.
>>>
>>> Yep.
>>>
>>>>
>>>>> + if (rte_mp_sendmsg(&mp_resp) < 0)
>>>>> + VDEV_LOG(ERR, "send vdev, %s, failed, %s",
>>>>> + devname, strerror(rte_errno));
>>>>> + num++;
>>>>
>>>> Some comments on what is going on here (why are we sending messages
>>>> in response? why multiple? who will receive these messages?) would
>>>> be nice.
>>>
>>> Yep, will explain that below.
>>>
>>>> I have a sneaking suspicion that you could've packed the response
>>>> into one single message, but i'm not completely sure what is going
>>>> on here, so maybe what you have here makes sense...
>>>
>>> What's happening here is that:
>>>
>>> a. Secondary process sends a sync request to ask for vdev in primary.
>>> b. Primary process receives the request, and send vdevs one by one.
>>> c. Primary process sends back reply, which indicates how many vdevs
>>> are sent.
>>>
>>> The reason we don't pack all vdevs in the reply message is that, the
>>> message length is RTE_MP_MAX_PARAM_LEN (256) in length. It's possible
>>> that we cannot pack all vdevs in the single reply message.
>>>
>>
>> OK. How does secondary know which vdevs are new and which aren't?
>
> This auto discovery is designed for secondary boot to know which vdevs
> are used in primary. So they are all new to the secondary process. For
> runtime vdev add in primary, we are going to rely on hotplug framework
> to tell the news to secondary processes.
>
>> Does it even matter how many vdevs primary has sent? Correct me if i'm
>> wrong, but it seems that you're only using sync request as kind of
>> synchronization mechanism, and are not actually expecting any useful
>> data in the reply. Which is OK, but in that case just don't bother
>> sending any data in the reply in the first place :)
>
> I would like to keep this information, so that secondary process can
> tell how many vdevs come from primary process (secondary process can
> definitely iterate the vdev list to know, but it's that straightforward).
>
OK, no strong objections here :)
--
Thanks,
Anatoly
next prev parent reply other threads:[~2018-04-20 15:40 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-04 15:30 [dpdk-dev] [PATCH 0/4] allow procinfo and pdump on eth vdev Jianfeng Tan
2018-03-04 15:30 ` [dpdk-dev] [PATCH 1/4] eal: bring forward multi-process channel init Jianfeng Tan
2018-03-04 15:30 ` [dpdk-dev] [PATCH 2/4] bus/vdev: bus scan by multi-process channel Jianfeng Tan
2018-03-05 9:36 ` Burakov, Anatoly
2018-03-06 0:50 ` Tan, Jianfeng
2018-03-07 14:00 ` Burakov, Anatoly
2018-03-12 3:22 ` Tan, Jianfeng
2018-03-04 15:30 ` [dpdk-dev] [PATCH 3/4] drivers/net: do not allocate rte_eth_dev_data privately Jianfeng Tan
2018-03-06 6:07 ` Matan Azrad
2018-03-06 8:55 ` Tan, Jianfeng
2018-03-07 6:00 ` Matan Azrad
2018-03-07 6:10 ` Matan Azrad
2018-03-12 3:40 ` Tan, Jianfeng
2018-03-04 15:30 ` [dpdk-dev] [PATCH 4/4] drivers/net: share vdev data to secondary process Jianfeng Tan
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 0/5] allow procinfo and pdump on eth vdev Jianfeng Tan
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 1/5] eal: bring forward multi-process channel init Jianfeng Tan
2018-04-20 8:16 ` Burakov, Anatoly
2018-04-20 14:08 ` Tan, Jianfeng
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 2/5] bus/vdev: add lock on vdev device list Jianfeng Tan
2018-04-20 8:26 ` Burakov, Anatoly
2018-04-20 14:19 ` Tan, Jianfeng
2018-04-20 15:16 ` Burakov, Anatoly
2018-04-20 15:23 ` Tan, Jianfeng
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 3/5] bus/vdev: bus scan by multi-process channel Jianfeng Tan
2018-04-20 8:41 ` Burakov, Anatoly
2018-04-20 14:28 ` Tan, Jianfeng
2018-04-20 15:19 ` Burakov, Anatoly
2018-04-20 15:32 ` Tan, Jianfeng
2018-04-20 15:39 ` Burakov, Anatoly [this message]
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 4/5] drivers/net: not use private eth dev data Jianfeng Tan
2018-04-19 16:50 ` [dpdk-dev] [PATCH v3 5/5] drivers/net: share vdev data to secondary process Jianfeng Tan
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 0/5] allow procinfo and pdump on eth vdev Jianfeng Tan
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 1/5] eal: bring forward multi-process channel init Jianfeng Tan
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 2/5] bus/vdev: add lock on vdev device list Jianfeng Tan
2018-04-23 9:47 ` Burakov, Anatoly
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 3/5] bus/vdev: bus scan by multi-process channel Jianfeng Tan
2018-04-23 9:54 ` Burakov, Anatoly
2018-04-24 5:22 ` Tan, Jianfeng
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 4/5] drivers/net: not use private eth dev data Jianfeng Tan
2018-04-20 16:57 ` [dpdk-dev] [PATCH v4 5/5] drivers/net: share vdev data to secondary process Jianfeng Tan
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 0/5] allow procinfo and pdump on eth vdev Jianfeng Tan
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 1/5] eal: bring forward multi-process channel init Jianfeng Tan
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 2/5] bus/vdev: add lock on vdev device list Jianfeng Tan
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 3/5] bus/vdev: bus scan by multi-process channel Jianfeng Tan
2018-04-24 10:09 ` Thomas Monjalon
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 4/5] drivers/net: not use private eth dev data Jianfeng Tan
2018-04-24 5:51 ` [dpdk-dev] [PATCH v5 5/5] drivers/net: share vdev data to secondary process Jianfeng Tan
2018-04-24 10:32 ` [dpdk-dev] [PATCH v5 0/5] allow procinfo and pdump on eth vdev Thomas Monjalon
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