Hi Maxime, > -----Original Message----- > From: Maxime Coquelin <maxime.coque...@redhat.com> > Sent: Thursday, September 23, 2021 4:34 PM > To: Eugenio Pérez <epere...@redhat.com>; Xia, Chenbo <chenbo....@intel.com> > Cc: dev@dpdk.org; Pei Zhang <pezh...@redhat.com>; Jason Wang > <jasow...@redhat.com> > Subject: Re: [PATCH] vhost: Clean iotlb cache on vring stop > > > > On 8/27/21 18:12, Eugenio Pérez wrote: > > Old IOVA cache entries are left when there is a change on virtio driver > > in VM. In case that all these old entries have iova addresses lesser > > than new iova entries, vhost code will need to iterate all the cache to > > find the new ones. In case of just a new iova entry needed for the new > > translations, this condition will last forever. > > > > This has been observed in virtio-net to testpmd's vfio-pci driver > > transition, reducing the performance from more than 10Mpps to less than > > 0.07Mpps if the hugepage address was higher than the networking > > buffers. Since all new buffers are contained in this new gigantic page, > > vhost needs to scan IOTLB_CACHE_SIZE - 1 for each translation at worst. > > > > Signed-off-by: Eugenio Pérez <epere...@redhat.com> > > Reported-by: Pei Zhang <pezh...@redhat.com> > > --- > > lib/vhost/vhost_user.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > > diff --git a/lib/vhost/vhost_user.c b/lib/vhost/vhost_user.c > > index 29a4c9af60..7de48f5333 100644 > > --- a/lib/vhost/vhost_user.c > > +++ b/lib/vhost/vhost_user.c > > @@ -2113,6 +2113,8 @@ vhost_user_get_vring_base(struct virtio_net **pdev, > > msg->size = sizeof(msg->payload.state); > > msg->fd_num = 0; > > > > + vhost_user_iotlb_flush_all(vq); > > + > > vring_invalidate(dev, vq); > > > > return RTE_VHOST_MSG_RESULT_REPLY; > > > > Reviewed-by: Maxime Coquelin <maxime.coque...@redhat.com>
So you will fix title and add fix tag when applying, right? /Chenbo > > Thanks, > Maxime
