From: John Hubbard <jhubbard@nvidia.com>
To: Andrew Morton <akpm@linux-foundation.org>,
Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ira Weiny <ira.weiny@intel.com>, <linux-rdma@vger.kernel.org>,
<linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>,
John Hubbard <jhubbard@nvidia.com>
Subject: [PATCH 1/1] IB/umem: use get_user_pages_fast() to pin DMA pages
Date: Fri, 8 Nov 2019 18:04:34 -0800 [thread overview]
Message-ID: <20191109020434.389855-2-jhubbard@nvidia.com> (raw)
In-Reply-To: <20191109020434.389855-1-jhubbard@nvidia.com>
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.
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Ira Weiny <ira.weiny@intel.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
drivers/infiniband/core/umem.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/drivers/infiniband/core/umem.c b/drivers/infiniband/core/umem.c
index 24244a2f68cc..3d664a2539eb 100644
--- a/drivers/infiniband/core/umem.c
+++ b/drivers/infiniband/core/umem.c
@@ -271,16 +271,13 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
sg = umem->sg_head.sgl;
while (npages) {
- down_read(&mm->mmap_sem);
- ret = get_user_pages(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);
+ ret = get_user_pages_fast(cur_base,
+ min_t(unsigned long, npages,
+ PAGE_SIZE /
+ sizeof(struct page *)),
+ gup_flags | FOLL_LONGTERM, page_list);
+ if (ret < 0)
goto umem_release;
- }
cur_base += ret * PAGE_SIZE;
npages -= ret;
@@ -288,8 +285,6 @@ struct ib_umem *ib_umem_get(struct ib_udata *udata, unsigned long addr,
sg = ib_umem_add_sg_table(sg, page_list, ret,
dma_get_max_seg_size(context->device->dma_device),
&umem->sg_nents);
-
- up_read(&mm->mmap_sem);
}
sg_mark_end(sg);
--
2.24.0
next prev parent reply other threads:[~2019-11-09 2:04 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-09 2:04 [PATCH 0/1] IB/umem: use get_user_pages_fast() to pin DMA pages John Hubbard
2019-11-09 2:04 ` John Hubbard [this message]
2019-11-11 3:21 ` [PATCH 1/1] " Ira Weiny
2019-11-11 21:44 ` John Hubbard
2019-11-12 20:29 ` Jason Gunthorpe
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