lkml.org 
[lkml]   [2014]   [Apr]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v2 01/24] input: Add ff-memless-next module
From
Date
On Wed, 2014-04-23 at 08:59 -0700, Dmitry Torokhov wrote:
> On Wed, Apr 23, 2014 at 02:12:59PM +0200, Oliver Neukum wrote:
> > On Tue, 2014-04-22 at 15:59 +0200, Michal Malý wrote:
> > > +/* Some devices might have a limit on how many uncombinable effects
> > > + * can be played at once */
> > > +static int mlnx_upload_conditional(struct mlnx_device *mlnxdev,
> > > + const struct ff_effect *effect)
> > > +{
> > > + struct mlnx_effect_command ecmd = {
> > > + .cmd = MLNX_UPLOAD_UNCOMB,
> > > + .u.uncomb.id = effect->id,
> > > + .u.uncomb.effect = effect
> > > + };
> > > + return mlnxdev->control_effect(mlnxdev->dev, mlnxdev->private,
> > > &ecmd);
> > > +}
> > > +
> >
> > This mean you are building the structure on the stack
> >
> > 1. Are you sure nobody retains a reference?
> > 2. That is needlessly inefficient
>
> Why is it inefficient?

The compiler has to include the data structure and then make
a memcopy to the stack. Instead a pointer to the predined structure
could be passed.

Regards
Oliver


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2014-04-23 19:41    [W:1.004 / U:0.072 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site