From: Thomas Monjalon <thomas.monjalon@6wind.com>
To: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 4/5] virtio: fix ring size negotiation
Date: Thu, 16 Apr 2015 09:38:46 +0200 [thread overview]
Message-ID: <8989447.p2fNsf6zhO@xps13> (raw)
In-Reply-To: <F52918179C57134FAEC9EA62FA2F962511AC2143@shsmsx102.ccr.corp.intel.com>
Guys, this is an example of what should not be done with emails formatting.
2015-04-16 06:26, Ouyang, Changchun:
>
> From: Stephen Hemminger [mailto:stephen@networkplumber.org]
> Sent: Thursday, April 16, 2015 1:48 PM
> To: Ouyang, Changchun
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH 4/5] virtio: fix ring size negotiation
This header is partly useless.
>
> No warning is needed, it just works.
Stephen, please do not top post. It makes harder to find what you are commenting.
>
> I know it works, but the upper user don’t know the descriptor number is reduced.
> I concern it is not so user-friendly here.
Changchun, please be sure the above text is quoted.
How are we supposed to understand who is speaking here?
All, please, take care of readers.
Thanks
> On Wed, Apr 15, 2015 at 8:39 PM, Ouyang, Changchun <changchun.ouyang@intel.com<mailto:changchun.ouyang@intel.com>> wrote:
>
>
> > -----Original Message-----
> > From: dev [mailto:dev-bounces@dpdk.org<mailto:dev-bounces@dpdk.org>] On Behalf Of Stephen
> > Hemminger
> > Sent: Wednesday, April 15, 2015 11:20 PM
> > To: dev@dpdk.org<mailto:dev@dpdk.org>
> > Subject: [dpdk-dev] [PATCH 4/5] virtio: fix ring size negotiation
> >
> > This fixes another of the issues with running virtio on non-KVM
> > envirionments. For example, Google Compute Engine reports a ring size of
> > 16K.
> >
> > If guest virtio requests more slots than available then the queue should just
>
> I suspect 'more' here should be 'less'?
>
> > be initialized to the smaller value.
> >
> > Conversely, if the number of descriptors requested exceeds the virtio host
> > queue size, then just silently use the smaller host size.
> >
> > Signed-off-by: Stephen Hemminger <stephen@networkplumber.org<mailto:stephen@networkplumber.org>>
> > ---
> > lib/librte_pmd_virtio/virtio_ethdev.c | 18 +++++++++++++-----
> > 1 file changed, 13 insertions(+), 5 deletions(-)
> >
> > diff --git a/lib/librte_pmd_virtio/virtio_ethdev.c
> > b/lib/librte_pmd_virtio/virtio_ethdev.c
> > index 3cb9c6a..db0232e 100644
> > --- a/lib/librte_pmd_virtio/virtio_ethdev.c
> > +++ b/lib/librte_pmd_virtio/virtio_ethdev.c
> > @@ -267,13 +267,21 @@ int virtio_dev_queue_setup(struct rte_eth_dev
> > *dev,
> > if (vq_size == 0) {
> > PMD_INIT_LOG(ERR, "%s: virtqueue does not exist",
> > __func__);
> > return -EINVAL;
> > - } else if (!rte_is_power_of_2(vq_size)) {
> > + }
> > +
> > + if (!rte_is_power_of_2(vq_size)) {
> > PMD_INIT_LOG(ERR, "%s: virtqueue size is not powerof 2",
> > __func__);
> > return -EINVAL;
> > - } else if (nb_desc != vq_size) {
> > - PMD_INIT_LOG(ERR, "Warning: nb_desc(%d) is not equal to
> > vq size (%d), fall to vq size",
> > - nb_desc, vq_size);
> > - nb_desc = vq_size;
> > + }
> > +
> > + if (nb_desc < vq_size) {
> > + if (!rte_is_power_of_2(nb_desc)) {
> > + PMD_INIT_LOG(ERR,
> > + "nb_desc(%u) size is not powerof 2",
> > + nb_desc);
> > + return -EINVAL;
> > + }
> > + vq_size = nb_desc;
> Don't we need a warning when nb_desc > vq_size?
>
> > }
> >
> > if (queue_type == VTNET_RQ) {
> > --
> > 2.1.4
>
>
next prev parent reply other threads:[~2015-04-16 7:39 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-15 15:20 [dpdk-dev] [PATCH 0/5] virtio driver fixes and cleanup Stephen Hemminger
2015-04-15 15:20 ` [dpdk-dev] [PATCH 1/5] virtio: remove useless new lines Stephen Hemminger
2015-04-16 3:41 ` Ouyang, Changchun
2015-04-15 15:20 ` [dpdk-dev] [PATCH 2/5] virtio: don't enable/disable rx modes unless supported Stephen Hemminger
2015-04-16 3:41 ` Ouyang, Changchun
2015-04-15 15:20 ` [dpdk-dev] [PATCH 3/5] virtio: don't set mac table unless negotiated Stephen Hemminger
2015-04-16 3:45 ` Ouyang, Changchun
2015-04-15 15:20 ` [dpdk-dev] [PATCH 4/5] virtio: fix ring size negotiation Stephen Hemminger
2015-04-16 3:39 ` Ouyang, Changchun
2015-04-16 5:47 ` Stephen Hemminger
2015-04-16 6:26 ` Ouyang, Changchun
2015-04-16 7:38 ` Thomas Monjalon [this message]
2015-04-16 17:30 ` Stephen Hemminger
2015-04-16 17:33 ` Stephen Hemminger
2015-04-15 15:20 ` [dpdk-dev] [PATCH 5/5] virtio: clarify feature bit handling Stephen Hemminger
2015-06-10 0:48 ` Stephen Hemminger
2015-06-11 5:56 ` Ouyang, Changchun
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