[ofw] ib_portinfo_record_t padding history?

[Hal Rosenstock]

On Wed, May 19, 2010 at 11:52 AM, Smith, Stan <stan.smith at intel.com> wrote:
> Hal Rosenstock wrote:
>> Hi Fab,
>>
>> On Wed, May 19, 2010 at 1:23 AM, Fab Tillier <ftillier at microsoft.com>
>> wrote:
>>> Hi Hal,
>>>
>>> Hal Rosenstock wrote on Tue, 18 May 2010 at 19:22:37
>>>
>>>>> AL_INLINE ib_net16_t AL_API
>>>>> ib_get_attr_offset(
>>>>>        IN              const   uint32_t  attr_size ) {
>>>>>        if( attr_size & 0x07 )
>>>>>                return( cl_hton16( (uint16_t)(attr_size >> 3) + 1 )
>>>>> );        else                return( cl_hton16(
>>>>> (uint16_t)(attr_size >> 3) ) ); }
>>>>>
>>>>> Linux
>>>>>
>>>>> static inline ib_net16_t AL_API
>>>>> ib_get_attr_offset(const uint32_t attr_size )
>>>>> {
>>>>>        return( cl_hton16( (uint16_t)(attr_size >> 3) ) );
>>>>> }
>>>>
>>>> Why does Windows have the if clause in ib_get_attr_off (and not
>>>> match the "Linux" version) ?
>>>
>>> So that the returned offset is not rounded down incorrect.  Say the
>>> attribute size is not a multiple of 8, the >> 3 would return a value
>>> 1 less than required.
>>>
>>> Not sure how the Linux code works properly, unless the structure
>>> sizes somehow get rounded to a multiple of 8.
>>
>> The record structs which are not modulo 8 bytes are explictly padded
>> out (e.g NodeRecord, LinkRecord, SMInfoRecord, InformInfoRecord). If
>> this is followed in the struct definitions, then the if clause is
>> never used.
>>
>> -- Hal
>>
>>> -Fab
>
> A little insurance never hurts;

Just a little extra unneeded/unused code. This if clause was removed
quite some time ago as I didn't see any log history to it so it prior
to git (when OpenSM was still in svn).

> although it can mask aligment problems.

Right.

-- Hal

> Perhaps the 'adjustment' should be turned into a nastygram?
>
> stan.
>