Re: [patch] lockdep: fix seqlock_init()

[Ingo Molnar]

* Andrew Morton <akpm@xxxxxxxx> wrote:

> > > > +#define seqlock_init(x)					\
> > > > +	do {						\
> > > > +		(x)->sequence = 0;			\
> > > > +		spin_lock_init(&(x)->lock);		\
> > > > +	} while (0)
> > > 
> > > This does not have to be a macro, does it?
> > 
> > Maybe it could be an __always_inline inline function (it has to be 
> > inlined to get the callsite based lock class key right)
> 
> the compiler darn better inline it, else we'll have an out-of-line 
> copy of everything in everywhere.

the compiler will do the uninlining happily if it sees a size advantage 
(when a single .c module calls the function several times), and creates 
a private per-object-file uninlined function. So an __always_inline 
would definitely be needed.

> > - but i'm not 
> > sure about the include file dependencies. Will probably work out fine as 
> > seqlock.h is supposed to be a late one in the order of inclusion - but i 
> > didnt want to make a blind bet.
> 
> seqlock.h already includes spinlock.h.

yes ... i just preserved the status quo.

	Ingo
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