Re: [PATCH RFC LKMM 1/7] tools/memory-model: Add extra ordering for locks and remove it for ordinary release/acquire

From: Akira Yokosawa
Date: Wed Sep 05 2018 - 11:04:24 EST


On 2018/09/06 0:00, Andrea Parri wrote:
> On Wed, Sep 05, 2018 at 11:33:08PM +0900, Akira Yokosawa wrote:
>> On 2018/09/05 09:21:51 +0200, Andrea Parri wrote:
>>> On Tue, Sep 04, 2018 at 03:09:49PM -0400, Alan Stern wrote:
>>>> On Tue, 4 Sep 2018, Andrea Parri wrote:
>>>>> Heh, your confusion might be the reflection of mine... ;-) That was
>>>>> indeed a long and not conclusive discussion (meaning there're pending
>>>>> issues); and I cannot claim to find "arguments" such as:
>>>>>
>>>>> "More than one kernel developer has expressed the opinion that
>>>>> the LKMM should enforce ordering of writes by locking."
>>>>>
>>>>> particularly helpful (I do tend to be convinced by arguments rather
>>>>> than by opinions). In fact, you can take the following as my only
>>>>> current "constructive argument" against the patch [1,2]:
>>>>>
>>>>> THE COMMIT MESSAGE IS RIDICULOUS; PLEASE EXPAND ON IT, AND DO
>>>>> SO BY LEVERAGING BOTH PROS AND CONS OF THE APPLIED CHANGES
>>>>
>>>> Do you have any concrete suggestions (i.e., some actual text) for
>>>> improvements to the patch description? Earlier in your message you
>>>> mentioned that Will's comment:
>>>>
>>>> LKMM offers stronger guarantees that can portably be relied upon
>>>> in the codebase.
>>>>
>>>> would make a good addition. Suitably edited, it could be added to the
>>>> description. I can think of a few other things myself, but I'd like to
>>>> hear your thoughts. Anything else?
>>>
>>> Yes: I do sometimes have the impression that your "rules" for trimming
>>> text in emails/replies are too aggressive...
>>
>> Andrea, by saying "Yes:", do you mean you have something else to be added?
>
> Indeed (examples in the trimmed text).

So, you mean just amending commit log does not work for you?

>
>
>> I don't think you do, but want to make sure.
>>
>> I'm a bit surprised to see all you wanted was the amendment of the
>> commit log...
>
> Well, I said that it was my only current constructive argument...

This thread is getting quite hard for me to follow...

Akira

>
> Andrea
>
>
>>
>> Akira
>>
>>>
>>> Andrea
>>>
>>>
>>>>
>>>> Alan
>>>>
>>