Re: [RFC PATCH 10/12] mm: add the buddy system interface

[Kamezawa Hiroyuki]

On 2015/06/09 19:04, Xishi Qiu wrote:
> On 2015/6/9 15:12, Kamezawa Hiroyuki wrote:
>
> > On 2015/06/04 22:04, Xishi Qiu wrote:
> > > Add the buddy system interface for address range mirroring feature.
> > > Allocate mirrored pages in MIGRATE_MIRROR list. If there is no mirrored pages
> > > left, use other types pages.
> > >
> > > Signed-off-by: Xishi Qiu <qiuxishi@xxxxxxxxxx>
> > > ---
> > >    mm/page_alloc.c | 40 +++++++++++++++++++++++++++++++++++++++-
> > >    1 file changed, 39 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > > index d4d2066..0fb55288 100644
> > > --- a/mm/page_alloc.c
> > > +++ b/mm/page_alloc.c
> > > @@ -599,6 +599,26 @@ static inline bool is_mirror_pfn(unsigned long pfn)
> > >
> > >        return false;
> > >    }
> > > +
> > > +static inline bool change_to_mirror(gfp_t gfp_flags, int high_zoneidx)
> > > +{
> > > +    /*
> > > +     * Do not alloc mirrored memory below 4G, because 0-4G is
> > > +     * all mirrored by default, and the list is always empty.
> > > +     */
> > > +    if (high_zoneidx < ZONE_NORMAL)
> > > +        return false;
> > > +
> > > +    /* Alloc mirrored memory for only kernel */
> > > +    if (gfp_flags & __GFP_MIRROR)
> > > +        return true;
> >
> > GFP_KERNEL itself should imply mirror, I think.
>
> Hi Kame,
>
> How about like this: #define GFP_KERNEL (__GFP_WAIT | __GFP_IO | __GFP_FS | __GFP_MIRROR) ?

Hm.... it cannot cover GFP_ATOMIC at el.

I guess, mirrored memory should be allocated if !__GFP_HIGHMEM or !__GFP_MOVABLE

thanks,
-Kame

Thanks,
-Kame



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