On 2/10/21 11:19 PM, John Hubbard wrote:

On 2/5/21 12:41 PM, Joao Martins wrote:

quoted

Add a unpin_user_page_range_dirty_lock() API which takes a starting page
and how many consecutive pages we want to unpin and optionally dirty.

To that end, define another iterator for_each_compound_range()
that operates in page ranges as opposed to page array.

For users (like RDMA mr_dereg) where each sg represents a
contiguous set of pages, we're able to more efficiently unpin
pages without having to supply an array of pages much of what
happens today with unpin_user_pages().

Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joao Martins <redacted>
---
  include/linux/mm.h |  2 ++
  mm/gup.c           | 62 ++++++++++++++++++++++++++++++++++++++++++++++
  2 files changed, 64 insertions(+)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index a608feb0d42e..b76063f7f18a 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h

@@ -1265,6 +1265,8 @@ static inline void put_page(struct page *page)
  void unpin_user_page(struct page *page);
  void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
  				 bool make_dirty);
+void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
+				      bool make_dirty);
  void unpin_user_pages(struct page **pages, unsigned long npages);
  
  /**

diff --git a/mm/gup.c b/mm/gup.c
index 467a11df216d..938964d31494 100644
--- a/mm/gup.c
+++ b/mm/gup.c

@@ -215,6 +215,32 @@ void unpin_user_page(struct page *page)
  }
  EXPORT_SYMBOL(unpin_user_page);
  
+static inline void compound_range_next(unsigned long i, unsigned long npages,
+				       struct page **list, struct page **head,
+				       unsigned int *ntails)

Yes, the new names look good, and I have failed to find any logic errors, so:

Reviewed-by: John Hubbard <jhubbard@nvidia.com>

Thanks again for all the input!