Re: [PATCH 2/2] md: dm-verity: allow parallel processing of bio blocks

From: Gilad Ben-Yossef
Date: Mon Mar 26 2018 - 02:32:02 EST


On Sun, Mar 25, 2018 at 9:41 PM, Yael Chemla <yael.chemla@xxxxxxxxxxxx> wrote:
> Allow parallel processing of bio blocks by moving to async. completion
> handling. This allows for better resource utilization of both HW and
> software based hash tfm and therefore better performance in many cases,
> depending on the specific tfm in use.
>
> Tested on ARM32 (zynq board) and ARM64 (Juno board).
> Time of cat command was measured on a filesystem with various file sizes.
> 12% performance improvement when HW based hash was used (ccree driver).
> SW based hash showed less than 1% improvement.
> CPU utilization when HW based hash was used presented 10% less context
> switch, 4% less cycles and 7% less instructions. No difference in
> CPU utilization noticed with SW based hash.
>
> Signed-off-by: Yael Chemla <yael.chemla@xxxxxxxxxxxx>
> ---
> drivers/md/dm-verity-fec.c | 10 +-
> drivers/md/dm-verity-fec.h | 7 +-
> drivers/md/dm-verity-target.c | 215 +++++++++++++++++++++++++++++++-----------
> drivers/md/dm-verity.h | 4 +-
> 4 files changed, 173 insertions(+), 63 deletions(-)

Reviewed-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx>

--
Gilad Ben-Yossef
Chief Coffee Drinker

"If you take a class in large-scale robotics, can you end up in a
situation where the homework eats your dog?"
-- Jean-Baptiste Queru