Re: [Fwd: Re: connector is missing in 2.6.12-rc2-mm1]

[Evgeniy Polyakov <johnpol@2ka.mipt.ru>]

On Fri, 2005-04-08 at 13:50 +1000, Herbert Xu wrote:
> On Fri, Apr 08, 2005 at 07:52:34AM +0400, Evgeniy Polyakov wrote:
> > On Fri, 2005-04-08 at 13:32 +1000, Herbert Xu wrote:
> > > On Fri, Apr 08, 2005 at 07:33:58AM +0400, Evgeniy Polyakov wrote:
> > > > On Fri, 2005-04-08 at 12:59 +1000, Herbert Xu wrote:
> > > > > Evgeniy Polyakov <johnpol@2ka.mipt.ru> wrote:
> > > > > >
> > > > > > atomic_dec_and_test() is more expensive than 2 barriers + atomic_dec(),
> > > > > > but in case of connector I think the price is not so high.
> > > > > 
> > > > > Can you list the platforms on which this is true?
> > > > 
> > > > sparc64, some mips [at least in UP].
> > > 
> > > Are you sure? The implementations of atomic_sub and atomic_sub_return
> > > (which correspond to atomic_dec and atomic_dec_and_test) seem to be
> > > comparable in cost on those two architectures.
> > 
> > mips has additional sync.
> 
> But atomic_dec + 2 barries is going to do the sync as well, no?

On UP do not.

> Cheers,
-- 
        Evgeniy Polyakov

Crash is better than data corruption -- Arthur Grabowski

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