Re: [PATCH V3] block: Mitigate lock unbalance caused by lock switching

[Asias He]

On 05/30/2012 02:28 PM, Tejun Heo wrote:
> Hello,
>
> On Wed, May 30, 2012 at 3:28 PM, Asias He<asias@xxxxxxxxxx>  wrote:
> > > Isn't the 'if' clause superfluous ? You could just do the assignment,
> > > e.g.,
> > >
> > > +       spin_lock_irq(lock);
> > > +       q->queue_lock =&q->__queue_lock;
> > > +       spin_unlock_irq(lock);
> >
> >
> > Well, this saves a if clause but adds an unnecessary assignment if the lock
> > is already internal lock.
>
> It's not hot path. Dirtying the cacheline there doesn't mean anything.
> I don't really care either way but making optimization argument is
> pretty silly here.

I don't care this neither ;-)

--
Asias
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