"David Z. Dai" <z...@linux.vnet.ibm.com> writes:
> On Thu, 2019-08-29 at 10:32 +0200, Eric Dumazet wrote:
>>
>> On 8/29/19 12:51 AM, David Dai wrote:
>> > For high speed adapter like Mellanox CX-5 card, it can reach upto
>> > 100 Gbits per second bandwidth. Currently htb already supports 64bit rate
>> > in tc utility. However police action rate and peakrate are still limited
>> > to 32bit value (upto 32 Gbits per second). Add 2 new attributes
>> > TCA_POLICE_RATE64 and TCA_POLICE_RATE64 in kernel for 64bit support
>> > so that tc utility can use them for 64bit rate and peakrate value to
>> > break the 32bit limit, and still keep the backward binary compatibility.
>> >
>> > Tested-by: David Dai <z...@linux.vnet.ibm.com>
>> > Signed-off-by: David Dai <z...@linux.vnet.ibm.com>
>> > ---
>> > include/uapi/linux/pkt_cls.h | 2 ++
>> > net/sched/act_police.c | 27 +++++++++++++++++++++++----
>> > 2 files changed, 25 insertions(+), 4 deletions(-)
>> >
>> > diff --git a/include/uapi/linux/pkt_cls.h b/include/uapi/linux/pkt_cls.h
>> > index b057aee..eb4ea4d 100644
>> > --- a/include/uapi/linux/pkt_cls.h
>> > +++ b/include/uapi/linux/pkt_cls.h
>> > @@ -159,6 +159,8 @@ enum {
>> > TCA_POLICE_AVRATE,
>> > TCA_POLICE_RESULT,
>> > TCA_POLICE_TM,
>> > + TCA_POLICE_RATE64,
>> > + TCA_POLICE_PEAKRATE64,
>> > TCA_POLICE_PAD,
>> > __TCA_POLICE_MAX
>> > #define TCA_POLICE_RESULT TCA_POLICE_RESULT
>>
>> Never insert new attributes, as this breaks compatibility with old binaries
>> (including
>> old kernels)
> Thanks for reviewing it!
> My change is only contained within the police part. I am trying to
> follow the same way htb and tbf support their 64 bit rate.
>
> I tested the old tc binary with the newly patched kernel. It works fine.
>
> I agree the newly compiled tc binary that has these 2 new attributes can
> cause backward compatibility issue when running on the old kernel.
>
> If can't insert new attribute, is there any
> comment/suggestion/alternative on how to support 64bit police rate and
> still keep the backward compatibility?
Just put the new attributes *after* PAD instead of before :)
-Toke
