Re: [PATCH] module: kzalloc mod->ref

Kyle McMartin
2009-01-14T15:59:28Z

On Wed, Jan 14, 2009 at 10:09:59AM +0100, Takashi Iwai wrote:
> At Tue, 13 Jan 2009 22:35:33 -0500,
> Kyle McMartin wrote:
> >
> > From: Kyle McMartin <kyle@redhat.com>
> >
> > Dynamically allocate mod->ref instead of fixing it in the struct module.
> > Reduces on disk space wasted in the module .ko, and kills a loop
> > initializing the local_t it contains since we can just kzalloc it.
> >
> > This matters when we're talking about large NR_CPUS.
> >
> > Signed-off-by: Kyle McMartin <kyle@redhat.com>
> > ---
> > The patch removing cacheline_aligned from struct module_ref should be
> > applied as well to cut down on the amount of memory we allocate. This
> > patch makes a nice stopgap until we have per_cpu module references.
> >
> > cheers, Kyle
>
> Similar patches (including mine) have been already posted, but no
> proceed until now...
> http://lkml.org/lkml/2008/11/11/315

Ah, sigh.

It would be nice to get this sorted out, since we're serious wasting
disk space for no good reason...

Although as Richard points out, dropping the cacheline_aligned might
drop networking performance (which, sigh, is also stupid) but allocating
128b * NR_CPUS is just a ridiculous amount of memory to waste for a
reference count...