[PATCH v12 2/6] mempool: add functions to get extra mempool info

[Paul Szczepanek]

On 29/05/2024 14:56, Morten Brørup wrote:
>> From: Paul Szczepanek [mailto:paul.szczepanek at arm.com]
>> Sent: Wednesday, 29 May 2024 12.23
>>
>> Add two functions:
>> - rte_mempool_get_mem_range - get virtual memory range
>> of the objects in the mempool,
>> - rte_mempool_get_obj_alignment - get alignment of
>> objects in the mempool.
>>
>> Add two tests that test these new functions.
>>
>> Signed-off-by: Paul Szczepanek <paul.szczepanek at arm.com>
>> Reviewed-by: Jack Bond-Preston <jack.bond-preston at foss.arm.com>
>> Reviewed-by: Nathan Brown <nathan.brown at arm.com>
>> ---
>>
>> +/**
>> + * @warning
>> + * @b EXPERIMENTAL: this API may change without prior notice.
>> + *
>> + * Get information about the memory range used by the mempool.
>> + *
>> + * @param[in] mp
>> + *   Pointer to an initialized mempool.
>> + * @param[out] mem_range_start
>> + *   Returns lowest address in mempool.
>> + * @param[out] mem_range_length
>> + *   Returns the length of the memory range containing all the addresses
>> + *   in the memory pool.
>> + * @return
>> + *   0 on success, -EINVAL if arguments are not valid.
>> + *
>> + **/
>> +__rte_experimental
>> +int rte_mempool_get_mem_range(struct rte_mempool *mp,
>> +		void **mem_range_start, size_t *mem_range_length);
> 
> Paul,
> 
> Could you please add one more output parameter "bool *mem_range_contiguous" to this function, returning true if the memory chunks are contiguous.
> 
> It will be useful instead of implementing get_memhdr_info() locally in this other patch series:
> https://inbox.dpdk.org/dev/MW4PR11MB58724AC82A34A3EEFEF78E898EF22@MW4PR11MB5872.namprd11.prod.outlook.com/
> 
> Please coordinate this change directly with Frank Du <frank.du at intel.com>.
> 
> -Morten
> 

Does this work for you?

int rte_mempool_get_mem_range(struct rte_mempool *mp,
		void **mem_range_start, size_t *mem_range_length,
		bool *contiguous)
{
	if (mp == NULL)
		return -EINVAL;

	void *address_low = (void *)UINTPTR_MAX;
	void *address_high = 0;
	size_t address_diff = 0;
	size_t mem_total_size = 0;
	struct rte_mempool_memhdr *hdr;

	/* go through memory chunks and find the lowest and highest addresses */
	STAILQ_FOREACH(hdr, &mp->mem_list, next) {
		if (address_low > hdr->addr)
			address_low = hdr->addr;
		if (address_high < RTE_PTR_ADD(hdr->addr, hdr->len))
			address_high = RTE_PTR_ADD(hdr->addr, hdr->len);
		mem_total_size += hdr->len;
	}

	/* check if mempool was not populated yet (no memory chunks) */
	if (address_low == (void *)UINTPTR_MAX)
		return -EINVAL;

	address_diff = (size_t)RTE_PTR_DIFF(address_high, address_low);
	if (mem_range_start != NULL)
		*mem_range_start = address_low;
	if (mem_range_length != NULL)
		*mem_range_length = address_diff;
	if (contiguous != NULL)
		*contiguous = (mem_total_size == address_diff) ? true : false;

	return 0;
}