***SPAM*** Re: [ofa-general] Re: [PATCH] opensm/osm_multicast.c: bug with joining/leaving mcast group

[Hal Rosenstock]

On Mon, Nov 10, 2008 at 2:18 PM, Yevgeny Kliteynik
<kliteyn at dev.mellanox.co.il> wrote:
> Hi Sasha,
>
> Sasha Khapyorsky wrote:
>>
>> Hi Yevgeny,
>>
>> On 16:36 Mon 10 Nov     , Yevgeny Kliteynik wrote:
>>>
>>> I think there's a bug in the osm_mgrp_add/remove_port functions.
>>> If some mcast group member has JoinState 0x1 (full member),
>>> and then new join from the same port received with JoinState
>>> 0x2 (non member), OpenSM will reduce number of full members
>>> of this group, which eventually might cause group deletion.
>>
>> Right, isn't this how things should work? When full member updates it
>> state to non member the number of full members are reduced, and then
>> last full member leaves the MC group is deleted (o15-0.2-1.9).
>
> I thought so too,

It's true; what you are seeing is the addition of send only non member
(to full member) and not eliminating full member.

>but turns out that it's wrong:
>
> o15-0.1.11: If SA supports UD multicast, then if an endport joins a
> multicast group as specified in o15-0.1.10:, SA shall replace the
> endport's current MCMemberRecord:JoinState component with the logical
> OR of the MCMemberRecord:JoinState component with the endport's current
> MCMemberRecord:JoinState component if the endport had joined this
> multicast group before.
>
> So the full member doesn't update its state to non-member, but rather
> adds additional bit to the JoinState (the non-member).

Right, a port can simultaneously be full member, non member, and send
only non member.

-- Hal

>
> -- Yevgeny
>
>> Sasha
>>
>>> Similar problem (only in logically opposite direction) happens
>>> when port tries to partially leave mcast group.
>>>
>>> This patch should fix it.
>>>
>>> Signed-off-by: Yevgeny Kliteynik <kliteyn at dev.mellanox.co.il>
>>> ---
>>>  opensm/opensm/osm_multicast.c |   33 +++++++++++----------------------
>>>  1 files changed, 11 insertions(+), 22 deletions(-)
>>>
>>> diff --git a/opensm/opensm/osm_multicast.c
>>> b/opensm/opensm/osm_multicast.c
>>> index d62d585..350fd22 100644
>>> --- a/opensm/opensm/osm_multicast.c
>>> +++ b/opensm/opensm/osm_multicast.c
>>> @@ -172,17 +172,11 @@ osm_mcm_port_t *osm_mgrp_add_port(IN osm_subn_t
>>> *subn, osm_log_t *log,
>>>                p_mgrp->last_change_id++;
>>>        }
>>>
>>> -       if ((join_state ^ prev_join_state) & IB_JOIN_STATE_FULL) {
>>> -               if (join_state & IB_JOIN_STATE_FULL) {
>>> -                       if (++p_mgrp->full_members == 1) {
>>> -                               mgrp_send_notice(subn, log, p_mgrp, 66);
>>> -                               p_mgrp->to_be_deleted = 0;
>>> -                       }
>>> -               } else if (--p_mgrp->full_members == 0) {
>>> -                       mgrp_send_notice(subn, log, p_mgrp, 67);
>>> -                       if (!p_mgrp->well_known)
>>> -                               p_mgrp->to_be_deleted = 1;
>>> -               }
>>> +       if ((join_state & IB_JOIN_STATE_FULL) &&
>>> +           !(prev_join_state & IB_JOIN_STATE_FULL) &&
>>> +           (++p_mgrp->full_members == 1)) {
>>> +               mgrp_send_notice(subn, log, p_mgrp, 66);
>>> +               p_mgrp->to_be_deleted = 0;
>>>        }
>>>
>>>        return (p_mcm_port);
>>> @@ -224,17 +218,12 @@ int osm_mgrp_remove_port(osm_subn_t *subn,
>>> osm_log_t *log, osm_mgrp_t *mgrp,
>>>
>>>        /* no more full members so the group will be deleted after
>>> re-route
>>>           but only if it is not a well known group */
>>> -       if ((port_join_state ^ new_join_state) & IB_JOIN_STATE_FULL) {
>>> -               if (port_join_state & IB_JOIN_STATE_FULL) {
>>> -                       if (--mgrp->full_members == 0) {
>>> -                               mgrp_send_notice(subn, log, mgrp, 67);
>>> -                               if (!mgrp->well_known)
>>> -                                       mgrp->to_be_deleted = 1;
>>> -                       }
>>> -               } else if (++mgrp->full_members == 1) {
>>> -                       mgrp_send_notice(subn, log, mgrp, 66);
>>> -                       mgrp->to_be_deleted = 0;
>>> -               }
>>> +       if ((port_join_state & IB_JOIN_STATE_FULL) &&
>>> +           !(new_join_state & IB_JOIN_STATE_FULL) &&
>>> +           (--mgrp->full_members == 0)) {
>>> +               mgrp_send_notice(subn, log, mgrp, 67);
>>> +               if (!mgrp->well_known)
>>> +                       mgrp->to_be_deleted = 1;
>>>        }
>>>
>>>        return ret;
>>> --
>>> 1.5.1.4
>>>
>>
>
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