[RFC PATCH V2 0/3] vhost: accelerate metadata access through vmap()

Jason Wang
2018-12-28T07:55:34Z

Hi:

This series tries to access virtqueue metadata through kernel virtual
address instead of copy_user() friends since they had too much
overheads like checks, spec barriers or even hardware feature
toggling.

Test shows about 24% improvement on TX PPS. It should benefit other
cases as well.

Changes from V1:
- instead of pinning pages, use MMU notifier to invalidate vmaps and
remap duing metadata prefetch
- fix build warning on MIPS

Please review

Jason Wang (3):
vhost: generalize adding used elem
vhost: fine grain userspace memory accessors
vhost: access vq metadata through kernel virtual address

drivers/vhost/net.c | 4 +-
drivers/vhost/vhost.c | 362 ++++++++++++++++++++++++++++++++++++++----
drivers/vhost/vhost.h | 15 +-
3 files changed, 348 insertions(+), 33 deletions(-)

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2.17.1