Re: [RFC PATCH 0/5] kmalloc-reclaimable caches

[Laura Abbott]

On 05/24/2018 08:52 AM, Vlastimil Babka wrote:
> On 05/24/2018 02:13 PM, Roman Gushchin wrote:
> > On Thu, May 24, 2018 at 01:00:06PM +0200, Vlastimil Babka wrote:
> > > Hi,
> > >
> > > - I haven't find any other obvious users for reclaimable kmalloc (yet)
> >
> > As I remember, ION memory allocator was discussed related to this theme:
> > https://lkml.org/lkml/2018/4/24/1288
>
> +CC Laura
>
> Yeah ION added the NR_INDIRECTLY_RECLAIMABLE_BYTES handling, which is
> adjusted to page granularity in patch 4. I'm not sure if it should use
> kmalloc as it seems to be allocating order-X pages, where kmalloc/slab
> just means extra overhead. But maybe if it doesn't allocate/free too
> frequently, it could work?

The page pool allocation is supposed to be a slow path but it's
one I'd rather not have too much overhead. It also just looks really odd
to be allocating higher order pages via kmalloc imho.
 
> > > I did a superset as IIRC somebody suggested that in the older threads or at LSF.
> >
> > This looks nice to me!
> >
> > Thanks!