| Message ID | 20200517020829.856731-1-jhubbard@nvidia.com |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | oradax: convert get_user_pages() --> pin_user_pages() | expand |
From: John Hubbard <jhubbard@nvidia.com> Date: Sat, 16 May 2020 19:08:29 -0700 > 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> Applied to sparc-next, thanks.
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; }
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> --- drivers/sbus/char/oradax.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) base-commit: 3d1c1e5931ce45b3a3f309385bbc00c78e9951c6