Re: Are the PathRecord reserved components really reserved?

[Vangelis Tasoulas <vangelis-S8y2klWGCOFhl2p70BpVqQ@public.gmane.org>]

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Thanks Ira,

I found the corresponding document.

Vangelis

On 08/25/2014 04:49 PM, Weiny, Ira wrote:
>>
>> Hello,
>>
>> I am looking into the OFED code for the component mask bits of the
>> PathRecord requests and I need some further explanation.
>>
>> The IB specification in section "15.2.5.16 PathRecord, table 207 PathRecord"
>> defines the first two components as "Reserved". Each one of them is 32 bits
>> long and the description of the first one is "Reserved"
>> while the description of the second reserved component is "Offset for
>> alignment".
> 
> 
> The IBTA has published errata to the 1.2.1 specification which includes the use of many reserved fields.
> 
> I believe these errata are public on their web site.
> 
> Ira
> 
>>
>> However, in the file "include/rdma/ib_sa.h" where the component mask bits for
>> the Path Records are defined, the 1st and 2nd component are combined
>> together under the name IB_SA_PATH_REC_SERVICE_ID.
>>
>>
>> #define IB_SA_PATH_REC_SERVICE_ID   (IB_SA_COMP_MASK( 0) |\
>>                                      IB_SA_COMP_MASK( 1))
>>
>>
>> The same definition exists in the OpenSM code in file "include/iba/ib_types.h"
>>
>>
>> /* Path Record Component Masks */
>> #define  IB_PR_COMPMASK_SERVICEID_MSB
>> (CL_HTON64(((uint64_t)1)<<0))
>> #define  IB_PR_COMPMASK_SERVICEID_LSB     (CL_HTON64(((uint64_t)1)<<1))
>> .....
>> .....
>> #define  IB_PR_COMPMASK_SERVICEID (IB_PR_COMPMASK_SERVICEID_MSB |
>> \
>>                                    IB_PR_COMPMASK_SERVICEID_LSB)
>>
>>
>> Why are these fields named as "SERVICE_ID"? I would expect something like
>> IB_SA_PATH_REC_RESERVED_1 and IB_SA_PATH_REC_RESERVED_2 according
>> to the specs. Are they really reserved or used, and if they are used, when does
>> this happen?
>>
>> Vangelis
> 



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