[dpdk-dev] [PATCH 2/2] mempool: fix comments for no contiguous flag

[Ferruh Yigit]

Hi Olivier,

On 9/21/2016 4:12 PM, Olivier Matz wrote:
> Hi Ferruh,
> 
> On 09/20/2016 06:17 PM, Ferruh Yigit wrote:
>> Fixes: ce94a51ff05c ("mempool: add flag for removing phys contiguous constraint")
>>
>> Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
>> ---
>>  lib/librte_mempool/rte_mempool.c | 4 +++-
>>  lib/librte_mempool/rte_mempool.h | 3 +++
>>  2 files changed, 6 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
>> index e96d14f..d767f39 100644
>> --- a/lib/librte_mempool/rte_mempool.c
>> +++ b/lib/librte_mempool/rte_mempool.c
>> @@ -340,7 +340,9 @@ rte_mempool_free_memchunks(struct rte_mempool *mp)
>>  }
>>  
>>  /* Add objects in the pool, using a physically contiguous memory
>> - * zone. Return the number of objects added, or a negative value
>> + * zone if MEMPOOL_F_NO_PHYS_CONTIG flag is not set.
>> + *
>> + * Return the number of objects added, or a negative value
>>   * on error.
>>   */
>>  int
>> diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
>> index 6fc331a..291c168 100644
>> --- a/lib/librte_mempool/rte_mempool.h
>> +++ b/lib/librte_mempool/rte_mempool.h
>> @@ -798,6 +798,9 @@ rte_mempool_free(struct rte_mempool *mp);
>>   * Add a virtually and physically contiguous memory chunk in the pool
>>   * where objects can be instanciated.
>>   *
>> + * mempool flag MEMPOOL_F_NO_PHYS_CONTIG changes behavior of the function
>> + * and removes physical contiguous constraint.
>> + *
>>   * @param mp
>>   *   A pointer to the mempool structure.
>>   * @param vaddr
>>
> 
> Not sure I'm getting why you add these comments, as I don't see any
> usage of MEMPOOL_F_NO_PHYS_CONTIG in rte_mempool_populate_phys().
> 
> Could you describe what makes you think the API comments are wrong here?

rte_mempool_populate_phys() now can get RTE_BAD_PHYS_ADDR as "paddr"
variable, and when paddr == RTE_BAD_PHYS_ADDR, function no more
quarantines that populated items are physically continuous.

Like how this is used in rte_mempool_populate_phys_tab(), if
MEMPOOL_F_NO_PHYS_CONTIG is set rte_mempool_populate_phys() called for
whole virtually continuous memory (len: pg_num * pg_size), so resulting
items may not be in physically continuous addresses, so function comment
becomes wrong.

Although MEMPOOL_F_NO_PHYS_CONTIG is not used within the
rte_mempool_populate_phys(), as far as I can see flag has a side effect
on the functionality.

And please help on wording if it is not accurate.


> 
> Thanks,
> Olivier
>