[PATCH next 0/3] iov: Optimise user copies

[David Laight <david.laight.linux@gmail.com>]

The speculation barrier in access_ok() is expensive.

The first patch removes the initial checks when reading the iovec[].
The checks are repeated before the actual copy.

The second patch uses 'user address masking' if supported.

The third removes a lot of code for single entry iovec[].

David Laight (3):
  Remove access_ok() from import_iovec()
  Use masked user accesses
  Optimise __import_iovec_ubuf()

 lib/iov_iter.c | 97 ++++++++++++++++++++++++++++++++------------------
 1 file changed, 63 insertions(+), 34 deletions(-)

-- 
2.39.5