Re: [PATCH 1/6 v5] Kernel DLPAR Infrastructure

Nathan Lynch
2009-10-29T03:59:21Z

On Thu, 2009-10-29 at 14:08 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2009-10-28 at 15:53 -0500, Nathan Fontenot wrote:
> > + struct device_node *dn;
> > + struct device_node *first_dn = NULL;
> > + struct device_node *last_dn = NULL;
> > + struct property *property;
> > + struct property *last_property = NULL;
> > + struct cc_workarea *ccwa;
> > + int cc_token;
> > + int rc;
> > +
> > + cc_token = rtas_token("ibm,configure-connector");
> > + if (cc_token == RTAS_UNKNOWN_SERVICE)
> > + return NULL;
> > +
> > + spin_lock(&workarea_lock);
> > +
> > + ccwa = (struct cc_workarea *)&workarea[0];
> > + ccwa->drc_index = drc_index;
> > + ccwa->zero = 0;
>
> Popping a free page with gfp (or just kmalloc'ing 4K) would avoid the
> need for the lock too.

Not kmalloc -- the alignment of the buffer isn't guaranteed when
slub/slab debug is on, and iirc the work area needs to be 4K-aligned.
__get_free_page should be fine, I think.