The patch titled
Subject: mm/gup: documentation fix for pin_user_pages*() APIs
has been removed from the -mm tree. Its filename was
mm-gup-documentation-fix-for-pin_user_pages-apis.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: John Hubbard <jhubbard@xxxxxxxxxx>
Subject: mm/gup: documentation fix for pin_user_pages*() APIs
All of the pin_user_pages*() API calls will cause pages to be dma-pinned.
As such, they are all suitable for either DMA, RDMA, and/or Direct IO.
The documentation should say so, but it was instead saying that three of
the API calls were only suitable for Direct IO. This was discovered when
a reviewer wondered why an API call that specifically recommended against
Case 2 (DMA/RDMA) was being used in a DMA situation [1].
Fix this by simply deleting those claims. The gup.c comments already
refer to the more extensive Documentation/core-api/pin_user_pages.rst,
which does have the correct guidance. So let's just write it once, there.
[1] https://lore.kernel.org/r/20200529074658.GM30374@kadam
Link: http://lkml.kernel.org/r/20200529084515.46259-1-jhubbard@xxxxxxxxxx
Signed-off-by: John Hubbard <jhubbard@xxxxxxxxxx>
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
Acked-by: Souptick Joarder <jrdr.linux@xxxxxxxxx>
Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/gup.c | 9 ---------
1 file changed, 9 deletions(-)
--- a/mm/gup.c~mm-gup-documentation-fix-for-pin_user_pages-apis
+++ a/mm/gup.c
@@ -2918,9 +2918,6 @@ EXPORT_SYMBOL_GPL(get_user_pages_fast);
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
* see Documentation/core-api/pin_user_pages.rst for further details.
- *
- * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
- * is NOT intended for Case 2 (RDMA: long-term pins).
*/
int pin_user_pages_fast(unsigned long start, int nr_pages,
unsigned int gup_flags, struct page **pages)
@@ -2994,9 +2991,6 @@ EXPORT_SYMBOL_GPL(pin_user_pages_fast_on
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
* see Documentation/core-api/pin_user_pages.rst for details.
- *
- * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
- * is NOT intended for Case 2 (RDMA: long-term pins).
*/
long pin_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, unsigned long nr_pages,
@@ -3030,9 +3024,6 @@ EXPORT_SYMBOL(pin_user_pages_remote);
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
* see Documentation/core-api/pin_user_pages.rst for details.
- *
- * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
- * is NOT intended for Case 2 (RDMA: long-term pins).
*/
long pin_user_pages(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
_
Patches currently in -mm which might be from jhubbard@xxxxxxxxxx are
