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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-10-29 16:03:31 -1000 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-10-30 11:38:10 -1000 |
| commit | 0fc810ae3ae110f9e2fcccce80fc8c8d62f97907 (patch) | |
| tree | 983d3b661ca5c20363d7066b01252b6473ee95a3 /Documentation/driver-api/firmware | |
| parent | 14b7d43c5c068cb9688a9fe68883f4340effb053 (diff) | |
| download | linux-master.tar.gz linux-master.tar.bz2 linux-master.zip | |
The barrier_nospec() in 64-bit copy_from_user() is slow. Instead use
pointer masking to force the user pointer to all 1's for an invalid
address.
The kernel test robot reports a 2.6% improvement in the per_thread_ops
benchmark [1].
This is a variation on a patch originally by Josh Poimboeuf [2].
Link: https://lore.kernel.org/202410281344.d02c72a2-oliver.sang@intel.com [1]
Link: https://lore.kernel.org/5b887fe4c580214900e21f6c61095adf9a142735.1730166635.git.jpoimboe@kernel.org [2]
Tested-and-reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/driver-api/firmware')
0 files changed, 0 insertions, 0 deletions