From: Ferruh Yigit <ferruh.yigit@intel.com>
To: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Cc: dev@dpdk.org, Thomas Monjalon <thomas.monjalon@6wind.com>,
Remy Horton <remy.horton@intel.com>
Subject: Re: [dpdk-dev] [PATCH] ethdev: fix wrong memset
Date: Mon, 23 Jan 2017 11:32:23 +0000 [thread overview]
Message-ID: <90752e37-444b-e2bf-6d4b-1bf2eda38deb@intel.com> (raw)
In-Reply-To: <20170123112445.GE10293@yliu-dev.sh.intel.com>
On 1/23/2017 11:24 AM, Yuanhan Liu wrote:
> On Mon, Jan 23, 2017 at 11:05:25AM +0000, Ferruh Yigit wrote:
>>>>>>>> lib/librte_ether/rte_ethdev.c | 2 +-
>>>>>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>>>>>
>>>>>>>> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
>>>>>>>> index 4790faf..61f44e2 100644
>>>>>>>> --- a/lib/librte_ether/rte_ethdev.c
>>>>>>>> +++ b/lib/librte_ether/rte_ethdev.c
>>>>>>>> @@ -225,7 +225,7 @@ struct rte_eth_dev *
>>>>>>>> return NULL;
>>>>>>>> }
>>>>>>>>
>>>>>>>> - memset(&rte_eth_devices[port_id], 0, sizeof(*eth_dev->data));
>>>>>>>> + memset(&rte_eth_dev_data[port_id], 0, sizeof(struct rte_eth_dev_data));
>>>>>>>
>>>>>>> Not directly related to the this issue, but, after fix, this may have
>>>>>>> issues with secondary process.
>>>>>>>
>>>>>>> There were patches sent to fix this.
>>>>>>
>>>>>> I mean this one:
>>>>>> http://dpdk.org/ml/archives/dev/2017-January/054422.html
>>>>>
>>>>> d948f596fee2 ("ethdev: fix port data mismatched in multiple process
>>>>> model") should have fixed it.
>>>>
>>>> Think about case, where secondary process uses a virtual PMD, which does
>>>> a rte_eth_dev_allocate() call, shouldn't this corrupt primary process
>>>> device data?
>>>
>>> Yes, it may. However, I doubt that's the typical usage.
>>
>> But this is a use case, and broken now,
>
> I thought it was broken since the beginning?
No, memset(&rte_eth_dev_data[port_id], ...) breaks it.
>
>> and fix is known.
>
> And there is already a fix?
http://dpdk.org/ml/archives/dev/2017-January/054422.html
>
>> Should be
>> fixed I think.
>
> Sure.
>
>>
>>> Besides that,
>>> most of virtual PMDs don't support Multipleprocess: git grep shows pcap
>>> is the only one that does claim Multipleprocess is supported.
>>
>> I guess you searched for NIC feature documentation for this.
>
> Yes.
>
>> But as far
>> as I know, all virtual drivers can be used in both primary and secondary
>> process.
>
> Maybe. But it becomes very error-prone to me then when vdev are involved
> in both primary and secondary process. I don't think current code is (or
> designed to be) strong enough to support that.
>
> I don't know it's allowed to use hotplug or not in the multiple process
> model. If yes, I think there would be many ways to break it.
>
> Honestly, the multiple process doesn't look like a good/clean design to
> me, especially when some piece of code claim to support it while some
> other doesn't.
>
> So my point was, yes, there is a bug, we should fix it. But it seems
> that there could be so many bugs if we hugely expand the test coverage
> of the multiple process feature.
Agreed.
>
> --yliu
>
next prev parent reply other threads:[~2017-01-23 11:32 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-20 8:04 Yuanhan Liu
2017-01-20 10:20 ` Thomas Monjalon
2017-01-20 10:34 ` Yuanhan Liu
2017-01-20 11:09 ` Ferruh Yigit
2017-01-20 18:05 ` Thomas Monjalon
2017-01-20 11:21 ` Ferruh Yigit
2017-01-20 15:27 ` Ferruh Yigit
2017-01-22 2:45 ` Yuanhan Liu
2017-01-23 9:41 ` Ferruh Yigit
2017-01-23 10:34 ` Yuanhan Liu
2017-01-23 11:05 ` Ferruh Yigit
2017-01-23 11:24 ` Yuanhan Liu
2017-01-23 11:32 ` Ferruh Yigit [this message]
2017-01-23 11:40 ` Yuanhan Liu
2017-01-23 11:56 ` Yuanhan Liu
2017-01-23 12:44 ` Ananyev, Konstantin
2017-01-23 12:52 ` Yuanhan Liu
2017-01-23 13:06 ` Ananyev, Konstantin
2017-01-23 13:09 ` Ferruh Yigit
2017-01-25 11:16 ` Thomas Monjalon
2017-01-28 13:14 ` Yuanhan Liu
2017-01-30 11:07 ` Remy Horton
2017-01-24 8:29 ` Remy Horton
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