From: "Michael S. Tsirkin" <mst@redhat.com>
To: Jason Wang <jasowang@redhat.com>
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
davem@davemloft.net
Subject: Re: [RFC PATCH V3 0/5] Hi:
Date: Fri, 4 Jan 2019 16:41:24 -0500 [thread overview]
Message-ID: <20190104163516-mutt-send-email-mst@kernel.org> (raw)
In-Reply-To: <20181229124656.3900-1-jasowang@redhat.com>
On Sat, Dec 29, 2018 at 08:46:51PM +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.
I think it's a reasonable approach.
However I need to look at whether and which mmu notifiers are invoked before
writeback. Do you know?
> Test shows about 24% improvement on TX PPS. It should benefit other
> cases as well.
>
> 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 | 416 +++++++++++++++++++++++++++++++++++++-----
> drivers/vhost/vhost.h | 15 +-
> 3 files changed, 384 insertions(+), 51 deletions(-)
>
> --
> 2.17.1
next prev parent reply other threads:[~2019-01-04 21:41 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-29 12:46 [RFC PATCH V3 0/5] Hi: Jason Wang
2018-12-29 12:46 ` [RFC PATCH V3 1/5] vhost: generalize adding used elem Jason Wang
2019-01-04 21:29 ` Michael S. Tsirkin
2019-01-05 0:33 ` Sean Christopherson
2019-01-07 7:00 ` Jason Wang
2019-01-07 14:50 ` Michael S. Tsirkin
2018-12-29 12:46 ` [RFC PATCH V3 2/5] vhost: fine grain userspace memory accessors Jason Wang
2018-12-29 12:46 ` [RFC PATCH V3 3/5] vhost: rename vq_iotlb_prefetch() to vq_meta_prefetch() Jason Wang
2018-12-29 12:46 ` [RFC PATCH V3 4/5] vhost: introduce helpers to get the size of metadata area Jason Wang
2018-12-29 12:46 ` [RFC PATCH V3 5/5] vhost: access vq metadata through kernel virtual address Jason Wang
2019-01-04 21:34 ` Michael S. Tsirkin
2019-01-07 8:40 ` Jason Wang
2019-01-02 20:47 ` [RFC PATCH V3 0/5] Hi: Michael S. Tsirkin
2019-01-07 2:19 ` Jason Wang
2019-01-07 3:28 ` Michael S. Tsirkin
2019-01-07 3:53 ` Jason Wang
2019-01-07 4:17 ` Michael S. Tsirkin
2019-01-07 6:50 ` Jason Wang
2019-01-07 14:37 ` Michael S. Tsirkin
2019-01-08 10:01 ` Jason Wang
2019-01-07 7:15 ` Dan Williams
2019-01-07 14:11 ` Michael S. Tsirkin
2019-01-07 21:39 ` Dan Williams
2019-01-07 22:25 ` Michael S. Tsirkin
2019-01-07 22:44 ` Dan Williams
2019-01-09 4:31 ` __get_user slower than get_user (was Re: [RFC PATCH V3 0/5] Hi:) Michael S. Tsirkin
2019-01-09 5:19 ` Linus Torvalds
2019-01-08 11:42 ` [RFC PATCH V3 0/5] Hi: Jason Wang
2019-01-04 21:41 ` Michael S. Tsirkin [this message]
2019-01-07 6:58 ` Jason Wang
2019-01-07 14:47 ` Michael S. Tsirkin
2019-01-08 10:12 ` Jason Wang
2019-01-11 8:59 ` Jason Wang
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