Re: [PATCH] buffer: Avoid setting buffer bits that are already set

[kemi]

On 2017å10æ24æ 09:21, Andi Kleen wrote:
> kemi <kemi.wang@xxxxxxxxx> writes:
>>
>> I'll see if I can find some
>>> time to implement the above in a nice way.
>>
>> Agree. Maybe something like test_and_set_bit() would be more suitable.
> 
> test_and_set_bit is a very different operation for the CPU because
> it is atomic for both. But we want the initial read to not
> be atomic.
> 

I meant to express the meaning of test before setting bit.
Apologize to make you confused.

> If you add special functions use a different variant that is only
> atomic for the set.
> 
> -Andi
>