Sure, have changed state of V1.
> -----Original Message----- > From: Gavin Hu (Arm Technology China) [mailto:gavin...@arm.com] > Sent: Monday, September 23, 2019 5:05 PM > To: Liu, Yong <yong....@intel.com>; maxime.coque...@redhat.com; Bie, Tiwei > <tiwei....@intel.com>; Wang, Zhihong <zhihong.w...@intel.com> > Cc: dev@dpdk.org > Subject: RE: [dpdk-dev] [PATCH v2 00/16] vhost packed ring performance > optimization > > Hi Marvin, > > A general comment for the series, could you mark V1 Superseded? > > /Gavin > > > -----Original Message----- > > From: dev <dev-boun...@dpdk.org> On Behalf Of Marvin Liu > > Sent: Friday, September 20, 2019 12:36 AM > > To: maxime.coque...@redhat.com; tiwei....@intel.com; > > zhihong.w...@intel.com > > Cc: dev@dpdk.org; Marvin Liu <yong....@intel.com> > > Subject: [dpdk-dev] [PATCH v2 00/16] vhost packed ring performance > > optimization > > > > Packed ring has more compact ring format and thus can significantly > > reduce the number of cache miss. It can lead to better performance. > > This has been approved in virtio user driver, on normal E5 Xeon cpu > > single core performance can raise 12%. > > > > http://mails.dpdk.org/archives/dev/2018-April/095470.html > > > > However vhost performance with packed ring performance was decreased. > > Through analysis, mostly extra cost was from the calculating of each > > descriptor flag which depended on ring wrap counter. Moreover, both > > frontend and backend need to write same descriptors which will cause > > cache contention. Especially when doing vhost enqueue function, virtio > > refill packed ring function may write same cache line when vhost doing > > enqueue function. This kind of extra cache cost will reduce the benefit > > of reducing cache misses. > > > > For optimizing vhost packed ring performance, vhost enqueue and dequeue > > function will be splitted into fast and normal path. > > > > Several methods will be taken in fast path: > > Uroll burst loop function into more pieces. > > Handle descriptors in one cache line simultaneously. > > Prerequisite check that whether I/O space can copy directly into mbuf > > space and vice versa. > > Prerequisite check that whether descriptor mapping is successful. > > Distinguish vhost used ring update function by enqueue and dequeue > > function. > > Buffer dequeue used descriptors as many as possible. > > Update enqueue used descriptors by cache line. > > Cache memory region structure for fast conversion. > > Disable sofware prefetch is hardware can do better. > > > > After all these methods done, single core vhost PvP performance with 64B > > packet on Xeon 8180 can boost 40%. > > > > v2: > > - Utilize compiler's pragma to unroll loop, distinguish clang/icc/gcc > > - Buffered dequeue used desc number changed to (RING_SZ - PKT_BURST) > > - Optimize dequeue used ring update when in_order negotiated > > > > Marvin Liu (16): > > vhost: add single packet enqueue function > > vhost: unify unroll pragma parameter > > vhost: add burst enqueue function for packed ring > > vhost: add single packet dequeue function > > vhost: add burst dequeue function > > vhost: rename flush shadow used ring functions > > vhost: flush vhost enqueue shadow ring by burst > > vhost: add flush function for burst enqueue > > vhost: buffer vhost dequeue shadow ring > > vhost: split enqueue and dequeue flush functions > > vhost: optimize enqueue function of packed ring > > vhost: add burst and single zero dequeue functions > > vhost: optimize dequeue function of packed ring > > vhost: cache address translation result > > vhost: check whether disable software pre-fetch > > vhost: optimize packed ring dequeue when in-order > > > > lib/librte_vhost/Makefile | 24 + > > lib/librte_vhost/rte_vhost.h | 27 + > > lib/librte_vhost/vhost.h | 33 + > > lib/librte_vhost/virtio_net.c | 1071 +++++++++++++++++++++++++++------ > > 4 files changed, 960 insertions(+), 195 deletions(-) > > > > -- > > 2.17.1 > > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you.
