Re: [PATCH RFC v2 1/2] qspinlock: Introducing a 4-byte queue spinlock implementation

[Waiman Long <waiman.long@hp.com>]

On 08/29/2013 01:03 PM, Alexander Fyodorov wrote:
> 29.08.2013, 19:25, "Waiman Long"<waiman.long@hp.com>:
>> What I have been thinking is to set a flag in an architecture specific
>> header file to tell if the architecture need a memory barrier. The
>> generic code will then either do a smp_mb() or barrier() depending on
>> the presence or absence of the flag. I would prefer to do more in the
>> generic code, if possible.
> If you use flag then you'll have to check it manually. It is better to add new smp_mb variant, I suggest calling it smp_mb_before_store(), and define it to barrier() on x86.

I am sorry that I was not clear in my previous mail. I mean a flag/macro 
for compile time checking rather than doing runtime checking.

Regards,
Longman