Re: [PATCH v1 01/25] net: core: device_rename: Use rwsem instead of a seqcount

Eric Dumazet
2020-05-20T03:18:25Z

On 5/19/20 7:57 PM, David Miller wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> Date: Wed, 20 May 2020 01:42:30 +0200
>
>> Stephen Hemminger <stephen@networkplumber.org> writes:
>>> On Wed, 20 May 2020 00:23:48 +0200
>>> Thomas Gleixner <tglx@linutronix.de> wrote:
>>>> No. We did not. -ENOTESTCASE
>>>
>>> Please try, it isn't that hard..
>>>
>>> # time for ((i=0;i<1000;i++)); do ip li add dev dummy$i type dummy; done
>>>
>>> real 0m17.002s
>>> user 0m1.064s
>>> sys 0m0.375s
>>
>> And that solves the incorrectness of the current code in which way?
>
> You mentioned that there wasn't a test case, he gave you one to try.
>

I do not think this would ever use device rename, nor netdev_get_name()

None of this stuff is fast path really.

# time for ((i=1;i<1000;i++)); do ip li add dev dummy$i type dummy; done

real 0m1.127s
user 0m0.270s
sys 0m1.039s