Re: [V9fs-developer] [PATCH 4/6] 9p: Remove an unnecessary memory barrier

[Dominique Martinet]

Matthew Wilcox wrote on Thu, Jun 28, 2018:
> How about this?
> 
> 	/*
> 	 * This barrier is needed to make sure any change made to req before
> -	 * the other thread wakes up will indeed be seen by the waiting side.
> +	 * the status change is visible to another thread
> 	 */

Yes, that sounds better.

This code is fairly old and I was wondering if the new WRITE_ONCE and
READ_ONCE macros would help but it looks like compile-time barriers only
so I do not think they would be enough...
Documentation/memory-barriers.txt still suggests something similar in
the "SLEEP AND WAKE-UP FUNCTIONS" section so I guess this is fine.


Thanks,
-- 
Dominique Martinet | Asmadeus