On Wed, May 08, 2024 at 10:14:00AM +0200, Mateusz Guzik wrote:
> Merely checking if the directory is encrypted happens for every open
> when using ext4, at the moment refing and unrefing the parent, costing 2
> atomics and serializing opens of different files.
>
> The most common case of encryption not being used can be checked for
> with RCU instead.
>
> Sample result from open1_processes -t 20 ("Separate file open/close")
> from will-it-scale on Sapphire Rapids (ops/s):
> before: 12539898
> after: 25575494 (+103%)
>
> v2:
> - add a comment justifying rcu usage, submitted by Eric Biggers
> - whack spurious IS_ENCRYPTED check from the refed case
>
> Signed-off-by: Mateusz Guzik <mjguzik@xxxxxxxxx>
> ---
> fs/crypto/hooks.c | 32 ++++++++++++++++++++++++++------
> 1 file changed, 26 insertions(+), 6 deletions(-)
Applied to https://git.kernel.org/pub/scm/fs/fscrypt/linux.git/log/?h=for-next
Thanks!
- Eric
