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

From: Waiman Long
Date: Thu Aug 29 2013 - 23:16:31 EST


On 08/29/2013 01:03 PM, Alexander Fyodorov wrote:
29.08.2013, 19:25, "Waiman Long"<waiman.long@xxxxxx>:
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
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