On Thu, Oct 19, 2017 at 5:58 PM, Andy Zhou <az...@ovn.org> wrote:
>
> On Thu, Oct 19, 2017 at 02:47 Pravin Shelar <pshe...@ovn.org> wrote:
>>
>> On Tue, Oct 17, 2017 at 12:36 AM, Andy Zhou <az...@ovn.org> wrote:
>> > OVS kernel datapath so far does not support Openflow meter action.
>> > This is the first stab at adding kernel datapath meter support.
>> > This implementation supports only drop band type.
>> >
>> > Signed-off-by: Andy Zhou <az...@ovn.org>
>> > ---
>> > net/openvswitch/Makefile | 1 +
>> > net/openvswitch/datapath.c | 14 +-
>> > net/openvswitch/datapath.h | 3 +
>> > net/openvswitch/meter.c | 604
>> > +++++++++++++++++++++++++++++++++++++++++++++
>> > net/openvswitch/meter.h | 54 ++++
>> > 5 files changed, 674 insertions(+), 2 deletions(-)
>> > create mode 100644 net/openvswitch/meter.c
>> > create mode 100644 net/openvswitch/meter.h
>> >
>> This patch mostly looks good. I have one comment below.
>>
>> > +static int ovs_meter_cmd_set(struct sk_buff *skb, struct genl_info
>> > *info)
>> > +{
>> > + struct nlattr **a = info->attrs;
>> > + struct dp_meter *meter, *old_meter;
>> > + struct sk_buff *reply;
>> > + struct ovs_header *ovs_reply_header;
>> > + struct ovs_header *ovs_header = info->userhdr;
>> > + struct datapath *dp;
>> > + int err;
>> > + u32 meter_id;
>> > + bool failed;
>> > +
>> > + meter = dp_meter_create(a);
>> > + if (IS_ERR_OR_NULL(meter))
>> > + return PTR_ERR(meter);
>> > +
>> > + reply = ovs_meter_cmd_reply_start(info, OVS_METER_CMD_SET,
>> > + &ovs_reply_header);
>> > + if (IS_ERR(reply)) {
>> > + err = PTR_ERR(reply);
>> > + goto exit_free_meter;
>> > + }
>> > +
>> > + ovs_lock();
>> > + dp = get_dp(sock_net(skb->sk), ovs_header->dp_ifindex);
>> > + if (!dp) {
>> > + err = -ENODEV;
>> > + goto exit_unlock;
>> > + }
>> > +
>> > + if (!a[OVS_METER_ATTR_ID]) {
>> > + err = -ENODEV;
>> > + goto exit_unlock;
>> > + }
>> > +
>> > + meter_id = nla_get_u32(a[OVS_METER_ATTR_ID]);
>> > +
>> > + /* Cannot fail after this. */
>> > + old_meter = lookup_meter(dp, meter_id);
>> I do not see RCU read lock taken here. This is not correctness issue
>> but it could cause RCU checker to spit out warning message. You could
>> do same trick that is done in get_dp() to avoid this issue.
>
> O.K.
>>
>>
>>
>> Can you also test the code with rcu sparse check config option enabled?
>
>
> Do you mean to sparse compile with CONFIG_PROVE_LOCKING and
> CONFIG_DENUG_OBJECTS_RCU_HEAD?
You could use all following options simultaneously:
CONFIG_PREEMPT
CONFIG_DEBUG_PREEMPT
CONFIG_DEBUG_SPINLOCK
CONFIG_DEBUG_ATOMIC_SLEEP
CONFIG_PROVE_RCU
CONFIG_DEBUG_OBJECTS_RCU_HEAD
Thanks,
Pravin.
