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| author | John Hubbard <jhubbard@nvidia.com> | 2020-05-16 19:08:29 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-05-17 12:46:10 -0700 |
| commit | 0a2576dae0328f6cb50cef9eee9ba760ddcc4691 (patch) | |
| tree | 2b305d406679983fec172d0be7ff6f59d9549625 /drivers/sbus | |
| parent | a012c1e866a65699c806ae4a35d267de29fe85e7 (diff) | |
| download | lwn-0a2576dae0328f6cb50cef9eee9ba760ddcc4691.tar.gz lwn-0a2576dae0328f6cb50cef9eee9ba760ddcc4691.zip | |
oradax: convert get_user_pages() --> pin_user_pages()
This code was using get_user_pages_fast(), in a "Case 2" scenario
(DMA/RDMA), using the categorization from [1]. That means that it's
time to convert the get_user_pages_fast() + put_page() calls to
pin_user_pages_fast() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Cc: David S. Miller <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/sbus')
| -rw-r--r-- | drivers/sbus/char/oradax.c | 8 |
1 files changed, 3 insertions, 5 deletions
diff --git a/drivers/sbus/char/oradax.c b/drivers/sbus/char/oradax.c index 8af216287a84..21b7cb6e7e70 100644 --- a/drivers/sbus/char/oradax.c +++ b/drivers/sbus/char/oradax.c @@ -410,9 +410,7 @@ static void dax_unlock_pages(struct dax_ctx *ctx, int ccb_index, int nelem) if (p) { dax_dbg("freeing page %p", p); - if (j == OUT) - set_page_dirty(p); - put_page(p); + unpin_user_pages_dirty_lock(&p, 1, j == OUT); ctx->pages[i][j] = NULL; } } @@ -425,13 +423,13 @@ static int dax_lock_page(void *va, struct page **p) dax_dbg("uva %p", va); - ret = get_user_pages_fast((unsigned long)va, 1, FOLL_WRITE, p); + ret = pin_user_pages_fast((unsigned long)va, 1, FOLL_WRITE, p); if (ret == 1) { dax_dbg("locked page %p, for VA %p", *p, va); return 0; } - dax_dbg("get_user_pages failed, va=%p, ret=%d", va, ret); + dax_dbg("pin_user_pages failed, va=%p, ret=%d", va, ret); return -1; } |