Re: [PATCH 2/3] qla2xxx: SAN congestion management(SCM) implementation.

[Shyam Sundar <ssundar@marvell.com>]

> On Jun 25, 2020, at 4:25 PM, James Smart <james.smart@broadcom.com> wrote:
> 
> 
> 
> On 6/11/2020 10:42 AM, Shyam Sundar wrote:
>> Seems like this (and a previous email) never made it to the reflector, resending.
>> 
>> The suggestions make sense to me, and I have made most of the recommended changes.
>> I was looking for some guidance on placements of the sim stats structures.
>> 
>>> On May 29, 2020, at 11:53 AM, Shyam Sundar <ssundar@marvell.com> wrote:
>>> 
>>> James,
>>>      I was thinking of adding a structures for tracking the target FPIN stats.
>>> 
>>> struct fc_rport_statistics {
>>> uint32_t link_failure_count;
>>> uint32_t loss_of_sync_count;
>>> ....
>>> }
>>> 
>>> under fc_rport:
>>> 
>>> struct fc_rport {
>>> 
>>> /* Private (Transport-managed) Attributes */
>>> struct fc_rport_statistics;
>>> 
>>>      For host FPIN stats (essentially the alarm & warning), was not sure if I should add them to the fc_host_statistics or
>>> define a new structure under the Private Attributes section within the fc_host_attrs/fc_vport.
> 
> my initial thought was the same
> 
>>> 
>>>      In theory, given that the host stats could be updated both via signals and FPIN, one could argue that it would make sense
>>> to maintain it with the current host statistics, but keeping it confined to transport will ensure we have a uniform way of handling
>>> congestion and peer congestion events.
> 
> but then I have the same thoughts as well. And the commonization of the parsing and incrementing makes a lot more sense.
> 
>>> 
>>>     Would appreciate your thoughts there.
>>> 
>>> Thanks
>>> Shyam
>>>    
> 
> 
> I would put them under the Dynamic attributes area in fc_host_attrs and fc_rport.
> fc_host_attrs:
> fpin_cn              incremented for each Congestion Notify FPIN
> cn_sig_warn     incremented for each congestion warning signal
> cn_sig_alarm    incremented for each congestion alarm signal
> fpin_dn             incremented for each Delivery Notification FPIN where attached wwpn is local port
> fpin_li                incremented for each Link Integrity FPIN where attached wwpn is local port
> 
> fc_rport:
> fpin_dn             incremented for each Delivery Notification FPIN where attached wwpn is the rport
> fpin_li               incremented for each Link Integrity FPIN where attached wwpn is the rport
> fpin_pcn           incremented for each Peer Congestion Notify FPIN where attached wwpn is the rport
> 
> For the cn_sig_xxx values, the driver would just increment them.
> For the fpin_xxx values - we'll augment the fc_host_fpin_rcv routine to parse the fpin and increment the fc_host or fc_rport counter.

Sounds good. Will do.

Thanks
Shyam
 
> 
> -- james