Re: [Bug fix PATCH v4] Reusing a resource structure allocated by bootmem

[Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>]

2013/04/19 8:28, Toshi Kani wrote:
> On Fri, 2013-04-19 at 08:33 +0900, Yasuaki Ishimatsu wrote:
>   :
> > > > +static struct resource *get_resource(gfp_t flags)
> > > > +{
> > > > +	struct resource *res = NULL;
> > > > +
> > > > +	spin_lock(&bootmem_resource_lock);
> > > > +	if (bootmem_resource.sibling) {
> > > > +		res = bootmem_resource.sibling;
> > > > +		bootmem_resource.sibling = res->sibling;
> > > > +		memset(res, 0, sizeof(struct resource));
> > > > +	}
> > > > +	spin_unlock(&bootmem_resource_lock);
> >
> > > I prefer to keep memset() outside of the spin lock.
> > >
> > > spin_lock(&bootmem_resource_lock);
> > > if (..) {
> > > 	:
> > > 	spin_unlock(&bootmem_resource_lock);
> > > 	memset(res, 0, sizeof(struct resource));
> > > } else {
> > > 	spin_unlock(&bootmem_resource_lock);
> > > 	res = kzalloc(sizeof(struct resource), flags);
> > > }
> >
> > Hmm. It is a little ugly. How about it?
> >
> > spin_lock(&bootmem_resource_lock);
> > if (bootmem_resource.sibling) {
> > 	res = bootmem_resource.sibling;
> > 	bootmem_resource.sibling = res->sibling;
> > }
> > spin_unlock(&bootmem_resource_lock);
> >
> > if (res)
> > 	memset(res, 0, sizeof(struct resource));
> > else	
> > 	res = kzalloc(sizeof(struct resource), flags);

> Sounds good to me.

Great. I'll update it.

Thanks,
Yasuaki Ishimatsu

> Thanks,
> -Toshi


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