Re: [PATCH net-next V6 7/8] net/dcb: Add an optional max rate attribute

(I try not to pay too much attention to the DCB stuff as it gives me nightmares)

It would comfort me to know if or which of:

Is 802.1au being implemented?

802.3bd?

There was some other standard involving active queue management at
this layer that I can't remember the alphabet soup for that must be
dead in the water at this point..

http://www.ieee802.org/1/files/public/docs2009/au-yasuda-10G-QCN-Implementation-1109.pdf


On Wed, Apr 4, 2012 at 5:23 PM, John Fastabend
[off-list ref] wrote:

On 4/4/2012 3:58 AM, Amir Vadai wrote:

quoted

Although not specified in 8021Qaz spec, it could be useful to enable drivers
whose HW supports setting a rate limit for an ETS TC. This patch adds this
optional attribute to DCB netlink. To use it, drivers should implement and
register the callbacks ieee_setmaxrate and ieee_getmaxrate. The units are 64
bits long and specified in Kbps to enable usage over both slow and very fast
networks.

Signed-off-by: Amir Vadai <redacted>
---

Or, Amir,

Two more comments inline really just minor nit picks but if your going
to roll new patch mind as well. I'll ack a patch with these changes.

quoted

 include/linux/dcbnl.h |    5 +++++
 include/net/dcbnl.h   |    2 ++
 net/dcb/dcbnl.c       |   21 +++++++++++++++++++++
 3 files changed, 28 insertions(+), 0 deletions(-)

diff --git a/include/linux/dcbnl.h b/include/linux/dcbnl.h
index 65a2562..ec8e372 100644
--- a/include/linux/dcbnl.h
+++ b/include/linux/dcbnl.h

@@ -67,6 +67,10 @@ struct ieee_ets {

      __u8    reco_prio_tc[IEEE_8021QAZ_MAX_TCS];
 };

annotate ieee_maxrate so implementers use it correctly per previous note.

quoted

+struct ieee_maxrate {
+     __u64   tc_maxrate[IEEE_8021QAZ_MAX_TCS];
+};
+
 /* This structure contains the IEEE 802.1Qaz PFC managed object
  *
  * @pfc_cap: Indicates the number of traffic classes on the local device

@@ -321,6 +325,7 @@ enum ieee_attrs {

      DCB_ATTR_IEEE_PEER_ETS,
      DCB_ATTR_IEEE_PEER_PFC,
      DCB_ATTR_IEEE_PEER_APP,
+     DCB_ATTR_IEEE_MAXRATE,
      __DCB_ATTR_IEEE_MAX
 };
 #define DCB_ATTR_IEEE_MAX (__DCB_ATTR_IEEE_MAX - 1)

diff --git a/include/net/dcbnl.h b/include/net/dcbnl.h
index f55c980..fc5d5dc 100644
--- a/include/net/dcbnl.h
+++ b/include/net/dcbnl.h

@@ -48,6 +48,8 @@ struct dcbnl_rtnl_ops {

      /* IEEE 802.1Qaz std */
      int (*ieee_getets) (struct net_device *, struct ieee_ets *);
      int (*ieee_setets) (struct net_device *, struct ieee_ets *);
+     int (*ieee_getmaxrate) (struct net_device *, struct ieee_maxrate *);
+     int (*ieee_setmaxrate) (struct net_device *, struct ieee_maxrate *);
      int (*ieee_getpfc) (struct net_device *, struct ieee_pfc *);
      int (*ieee_setpfc) (struct net_device *, struct ieee_pfc *);
      int (*ieee_getapp) (struct net_device *, struct dcb_app *);

diff --git a/net/dcb/dcbnl.c b/net/dcb/dcbnl.c
index 36f37af..d3df048 100644
--- a/net/dcb/dcbnl.c
+++ b/net/dcb/dcbnl.c

@@ -178,6 +178,8 @@ static const struct nla_policy dcbnl_ieee_policy[DCB_ATTR_IEEE_MAX + 1] = {

      [DCB_ATTR_IEEE_ETS]         = {.len = sizeof(struct ieee_ets)},
      [DCB_ATTR_IEEE_PFC]         = {.len = sizeof(struct ieee_pfc)},
      [DCB_ATTR_IEEE_APP_TABLE]   = {.type = NLA_NESTED},
+     [DCB_ATTR_IEEE_MAXRATE]   = {.len = sizeof(struct ieee_maxrate)},
+

spurious newline remove it

quoted

 };

 static const struct nla_policy dcbnl_ieee_app[DCB_ATTR_IEEE_APP_MAX + 1] = {

@@ -1246,6 +1248,17 @@ static int dcbnl_ieee_fill(struct sk_buff *skb, struct net_device *netdev)

                      goto nla_put_failure;
      }

+     if (ops->ieee_getmaxrate) {
+             struct ieee_maxrate maxrate;
+             err = ops->ieee_getmaxrate(netdev, &maxrate);
+             if (!err) {
+                     err = nla_put(skb, DCB_ATTR_IEEE_MAXRATE,
+                                     sizeof(maxrate), &maxrate);

align sizeof with skb

Thanks,
John
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