Re: [PATCH] ion: Consider ion pool pages as indirectly reclaimable

[vjitta]

On 2018-04-27 10:40, vjitta@xxxxxxxxxxxxxx wrote:
> On 2018-04-25 21:17, Laura Abbott wrote:
> > On 04/24/2018 08:43 PM, vjitta@xxxxxxxxxxxxxx wrote:
> > > From: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
> > >
> > > An issue is observed where mallocs are failing due to overcommit 
> > > failure.
> > > The failure happens when there is high ION page pool since ION page
> > > pool is not considered reclaimable by the overcommit calculation 
> > > code.
> > > This change considers ion pool pages as indirectly reclaimable and 
> > > thus
> > > accounted as available memory in the overcommit calculation.
> > >
> > > Signed-off-by: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
> > > ---
> > >   drivers/staging/android/ion/ion_page_pool.c | 5 +++++
> > >   1 file changed, 5 insertions(+)
> > >
> > > diff --git a/drivers/staging/android/ion/ion_page_pool.c 
> > > b/drivers/staging/android/ion/ion_page_pool.c
> > > index db8f614..9bc56eb 100644
> > > --- a/drivers/staging/android/ion/ion_page_pool.c
> > > +++ b/drivers/staging/android/ion/ion_page_pool.c
> > > @@ -32,6 +32,9 @@ static void ion_page_pool_add(struct ion_page_pool 
> > > *pool, struct page *page)
> > >   		list_add_tail(&page->lru, &pool->low_items);
> > >   		pool->low_count++;
> > >   	}
> > > +
> > > +	mod_node_page_state(page_pgdat(page), 
> > > NR_INDIRECTLY_RECLAIMABLE_BYTES,
> > > +			    (1 << (PAGE_SHIFT + pool->order)));
> > >   	mutex_unlock(&pool->mutex);
> > >   }
> > >   @@ -50,6 +53,8 @@ static struct page *ion_page_pool_remove(struct 
> > > ion_page_pool *pool, bool high)
> > >   	}
> > >     	list_del(&page->lru);
> > > +	mod_node_page_state(page_pgdat(page), 
> > > NR_INDIRECTLY_RECLAIMABLE_BYTES,
> > > +			    -(1 << (PAGE_SHIFT + pool->order)));
> > >   	return page;
> > >   }
> >
> > I'm sure this fixes the problem but I don't think we want to
> > start throwing page adjustments into Ion. Why isn't this
> > memory already considered reclaimable by existing calculations?
> >
> > Thanks,
> > Laura
>
> You can refer to discussion here https://lkml.org/lkml/2018/3/5/361 
> introducing
> NR_INDIRECTLY_RECLAIMABLE_BYTES for the memory which is not currently 
> considered
> as reclaimable
>
> Thanks,
> Vijay

There was also discussion specific to ion in that thread you can find it 
here
https://lkml.org/lkml/2018/4/25/642

Thanks,
Vijay