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Subject: Re: [PATCH rdma-next] RDMA/core: Use pr_warn_ratelimited
To:     Leon Romanovsky <leon@kernel.org>,
        Parav Pandit <parav@mellanox.com>
CC:     "dledford@redhat.com" <dledford@redhat.com>,
        "jgg@ziepe.ca" <jgg@ziepe.ca>,
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From:   "Liuyixian (Eason)" <liuyixian@huawei.com>
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Date:   Wed, 6 Nov 2019 10:15:15 +0800
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On 2019/11/5 22:41, Leon Romanovsky wrote:
> On Tue, Nov 05, 2019 at 04:09:12AM +0000, Parav Pandit wrote:
>> Hi Yixian Liu,
>>
>>> -----Original Message-----
>>> From: linux-rdma-owner@vger.kernel.org <linux-rdma-
>>> owner@vger.kernel.org> On Behalf Of Yixian Liu
>>> Sent: Monday, November 4, 2019 9:48 PM
>>> To: dledford@redhat.com; jgg@ziepe.ca
>>> Cc: Parav Pandit <parav@mellanox.com>; leon@kernel.org; linux-
>>> rdma@vger.kernel.org; linuxarm@huawei.com
>>> Subject: [PATCH rdma-next] RDMA/core: Use pr_warn_ratelimited
>>>
>>> This warning can be triggered easily when adding a large number of VLANs
>>> while the capacity of GID table is small.
>>>
>>> Fixes: 598ff6bae689 ("IB/core: Refactor GID modify code for RoCE")
>>> Signed-off-by: Yixian Liu <liuyixian@huawei.com>
>>> ---
>>>  drivers/infiniband/core/cache.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>> Thanks for the patch. However, vlan netdevice addition is an administrative operation allowed to process which has CAP_NET_ADMIN privilege.
>> So large number of VLAN addition by a user for a RoCE device whose GID capacity is small is constrained operation.
>> Therefore, we shouldn't be rate limiting it.
>> By rate limiting we miss the information about any bugs in GID cache management.
>> At best we can convert it to dev_dbg() so that we still get the necessary debug information when needed.
>> I wanted to convert them trace functions which will allow us to more debug level prints such as netdev name, vlan etc.
>> I think I remember comment from Leon too while working on it, but it was long haul that time.
> 
> I wanted to work on it, but it never happened.

I see, thanks.

> 
> Thanks
> 
> .
>