Re: [PATCH 2/2] mm: remove extra ZONE_DEVICE struct page refcount

2020-09-28 Thread Bharata B Rao
On Fri, Sep 25, 2020 at 01:44:42PM -0700, Ralph Campbell wrote: > ZONE_DEVICE struct pages have an extra reference count that complicates the > code for put_page() and several places in the kernel that need to check the > reference count to see that a page is not being used (gup, compaction, > migr

Re: [PATCH 2/2] mm: remove extra ZONE_DEVICE struct page refcount

2020-09-28 Thread Ralph Campbell
On 9/25/20 11:41 PM, Christoph Hellwig wrote: On Fri, Sep 25, 2020 at 01:44:42PM -0700, Ralph Campbell wrote: ZONE_DEVICE struct pages have an extra reference count that complicates the code for put_page() and several places in the kernel that need to check the reference count to see that a pa

Re: [PATCH 2/2] mm: remove extra ZONE_DEVICE struct page refcount

2020-09-25 Thread Christoph Hellwig
On Fri, Sep 25, 2020 at 01:44:42PM -0700, Ralph Campbell wrote: > ZONE_DEVICE struct pages have an extra reference count that complicates the > code for put_page() and several places in the kernel that need to check the > reference count to see that a page is not being used (gup, compaction, > migr

[PATCH 2/2] mm: remove extra ZONE_DEVICE struct page refcount

2020-09-25 Thread Ralph Campbell
ZONE_DEVICE struct pages have an extra reference count that complicates the code for put_page() and several places in the kernel that need to check the reference count to see that a page is not being used (gup, compaction, migration, etc.). Clean up the code so the reference count doesn't need to b