On Wed, Jan 23, 2019 at 05:55:52PM +0800, Jason Wang wrote: > 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. ok I think this addresses most comments but it's a big change and we just started 1.1 review so to pls give me a week to review this ok? > Changes from V3: > - don't try to use vmap for file backed pages > - rebase to master > Changes from V2: > - fix buggy range overlapping check > - tear down MMU notifier during vhost ioctl to make sure invalidation > request can read metadata userspace address and vq size without > holding vq mutex. > Changes from V1: > - instead of pinning pages, use MMU notifier to invalidate vmaps and > remap duing metadata prefetch > - fix build warning on MIPS > > Jason Wang (5): > vhost: generalize adding used elem > vhost: fine grain userspace memory accessors > vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch() > vhost: introduce helpers to get the size of metadata area > vhost: access vq metadata through kernel virtual address > > drivers/vhost/net.c | 4 +- > drivers/vhost/vhost.c | 441 +++++++++++++++++++++++++++++++++++++----- > drivers/vhost/vhost.h | 15 +- > mm/shmem.c | 1 + > 4 files changed, 410 insertions(+), 51 deletions(-) > > -- > 2.17.1
