Messages in this thread | | | Date | Fri, 9 Jan 2015 06:07:34 -0800 | From | "Paul E. McKenney" <> | Subject | Re: [PATCH tip/core/rcu 01/14] rcu: Protect rcu_boost() lockless accesses with ACCESS_ONCE() |
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On Fri, Jan 09, 2015 at 02:56:14PM +0100, Peter Zijlstra wrote: > On Fri, Jan 09, 2015 at 05:49:54AM -0800, Paul E. McKenney wrote: > > > That reminds me, I think the new conversion for stores will most likely > > > introduce silly arg bugs: > > > > > > - ACCESS_ONCE(a) = b; > > > + ASSIGN_ONCE(b, a); > > > > I was planning to do mine by hand for this sort of reason. > > > > Or are you thinking of something more subtle than the case where > > "b" is an unparenthesized comma-separated expression? > > I think he's revering to the wrong way around-ness of the thing. > > Its a bit of a mixed bag on assignments, but for instance > rcu_assign_pointer() takes them the right way around, as does > atomic_set(). > > So yes, I think the ASSIGN_ONCE() thing got the arguments the wrong way > around.
Ah, yes, I had forgotten about this point.
> We could maybe still change it, before its in too long ?
I would be in favor. Any objections? ;-)
Thanx, Paul
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