Re: [PATCH 1/3] mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES
From: Roman Gushchin
Date: Wed Apr 25 2018 - 08:53:01 EST
On Wed, Apr 25, 2018 at 09:19:29AM +0530, Vijayanand Jitta wrote:
> >>>> Idk, I don't like the idea of adding a counter outside of the vm counters
> >>>> infrastructure, and I definitely wouldn't touch the exposed
> >>>> nr_slab_reclaimable and nr_slab_unreclaimable fields.
> >>> We would be just making the reported values more precise wrt reality.
> >> It depends on if we believe that only slab memory can be reclaimable
> >> or not. If yes, this is true, otherwise not.
> >> My guess is that some drivers (e.g. networking) might have buffers,
> >> which are reclaimable under mempressure, and are allocated using
> >> the page allocator. But I have to look closer...
> > One such case I have encountered is that of the ION page pool. The page pool
> > registers a shrinker. When not in any memory pressure page pool can go high
> > and thus cause an mmap to fail when OVERCOMMIT_GUESS is set. I can send
> > a patch to account ION page pool pages in NR_INDIRECTLY_RECLAIMABLE_BYTES.
This is exactly what I've expected.
> > Thanks,
> > Vinayak
> As Vinayak mentioned NR_INDIRECTLY_RECLAIMABLE_BYTES can be used to solve the issue
> with ION page pool when OVERCOMMIT_GUESS is set, the patch for the same can be
> found here https://lkml.org/lkml/2018/4/24/1288
This makes perfect sense to me.
Please, fell free to add:
Acked-by: Roman Gushchin <guro@xxxxxx>