Commit 4789fcdd authored by John Hubbard's avatar John Hubbard Committed by Linus Torvalds
Browse files

IB/umem: use get_user_pages_fast() to pin DMA pages 

And get rid of the mmap_sem calls, as part of that.  Note that
get_user_pages_fast() will, if necessary, fall back to
__gup_longterm_unlocked(), which takes the mmap_sem as needed.

Link: http://lkml.kernel.org/r/20200107224558.2362728-10-jhubbard@nvidia.com


Signed-off-by: default avatarJohn Hubbard <jhubbard@nvidia.com>
Reviewed-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Reviewed-by: default avatarIra Weiny <ira.weiny@intel.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Cc: Björn Töpel <bjorn.topel@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent f4000fdf

drivers/infiniband/core/umem.c

+6 −11
Original line number Diff line number Diff line
@@ -257,16 +257,13 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 
	sg = umem->sg_head.sgl;



	while (npages) {

		down_read(&mm->mmap_sem);

		ret = get_user_pages(cur_base,

		ret = get_user_pages_fast(cur_base,

					  min_t(unsigned long, npages,

					   PAGE_SIZE / sizeof (struct page *)),

				     gup_flags | FOLL_LONGTERM,

				     page_list, NULL);

		if (ret < 0) {

			up_read(&mm->mmap_sem);

						PAGE_SIZE /

						sizeof(struct page *)),

					  gup_flags | FOLL_LONGTERM, page_list);

		if (ret < 0)

			goto umem_release;

		}



		cur_base += ret * PAGE_SIZE;

		npages   -= ret;
@@ -274,8 +271,6 @@ struct ib_umem *ib_umem_get(struct ib_device *device, unsigned long addr, 
		sg = ib_umem_add_sg_table(sg, page_list, ret,

			dma_get_max_seg_size(device->dma_device),

			&umem->sg_nents);



		up_read(&mm->mmap_sem);

	}



	sg_mark_end(sg);