Re: [dpdk-dev] [PATCH 02/36] mempool: replace elt_size by total_elt_size

["Wiles, Keith" <keith.wiles@intel.com>]

>In some mempool functions, we use the size of the elements as arguments or in
>variables. There is a confusion between the size including or not including
>the header and trailer.
>
>To avoid this confusion:
>- update the API documentation
>- rename the variables and argument names as "elt_size" when the size does not
>  include the header and trailer, or else as "total_elt_size".
>
>Signed-off-by: Olivier Matz <olivier.matz@6wind.com>

Acked by: Keith Wiles <keith.wiles@intel.com>
>---
> lib/librte_mempool/rte_mempool.c | 21 +++++++++++----------
> lib/librte_mempool/rte_mempool.h | 19 +++++++++++--------
> 2 files changed, 22 insertions(+), 18 deletions(-)
>
>diff --git a/lib/librte_mempool/rte_mempool.c b/lib/librte_mempool/rte_mempool.c
>index ce78476..90b5b1b 100644
>--- a/lib/librte_mempool/rte_mempool.c
>+++ b/lib/librte_mempool/rte_mempool.c
>@@ -156,13 +156,13 @@ mempool_add_elem(struct rte_mempool *mp, void *obj, uint32_t obj_idx,
>  *
>  * Given the pointer to the memory, and its topology in physical memory
>  * (the physical addresses table), iterate through the "elt_num" objects
>- * of size "total_elt_sz" aligned at "align". For each object in this memory
>+ * of size "elt_sz" aligned at "align". For each object in this memory
>  * chunk, invoke a callback. It returns the effective number of objects
>  * in this memory. */
> uint32_t
>-rte_mempool_obj_iter(void *vaddr, uint32_t elt_num, size_t elt_sz, size_t align,
>-	const phys_addr_t paddr[], uint32_t pg_num, uint32_t pg_shift,
>-	rte_mempool_obj_iter_t obj_iter, void *obj_iter_arg)
>+rte_mempool_obj_iter(void *vaddr, uint32_t elt_num, size_t total_elt_sz,
>+	size_t align, const phys_addr_t paddr[], uint32_t pg_num,
>+	uint32_t pg_shift, rte_mempool_obj_iter_t obj_iter, void *obj_iter_arg)
> {
> 	uint32_t i, j, k;
> 	uint32_t pgn, pgf;
>@@ -178,7 +178,7 @@ rte_mempool_obj_iter(void *vaddr, uint32_t elt_num, size_t elt_sz, size_t align,
> 	while (i != elt_num && j != pg_num) {
> 
> 		start = RTE_ALIGN_CEIL(va, align);
>-		end = start + elt_sz;
>+		end = start + total_elt_sz;
> 
> 		/* index of the first page for the next element. */
> 		pgf = (end >> pg_shift) - (start >> pg_shift);
>@@ -255,6 +255,7 @@ mempool_populate(struct rte_mempool *mp, size_t num, size_t align,
> 		mempool_obj_populate, &arg);
> }
> 
>+/* get the header, trailer and total size of a mempool element. */
> uint32_t
> rte_mempool_calc_obj_size(uint32_t elt_size, uint32_t flags,
> 	struct rte_mempool_objsz *sz)
>@@ -332,17 +333,17 @@ rte_mempool_calc_obj_size(uint32_t elt_size, uint32_t flags,
>  * Calculate maximum amount of memory required to store given number of objects.
>  */
> size_t
>-rte_mempool_xmem_size(uint32_t elt_num, size_t elt_sz, uint32_t pg_shift)
>+rte_mempool_xmem_size(uint32_t elt_num, size_t total_elt_sz, uint32_t pg_shift)
> {
> 	size_t n, pg_num, pg_sz, sz;
> 
> 	pg_sz = (size_t)1 << pg_shift;
> 
>-	if ((n = pg_sz / elt_sz) > 0) {
>+	if ((n = pg_sz / total_elt_sz) > 0) {
> 		pg_num = (elt_num + n - 1) / n;
> 		sz = pg_num << pg_shift;
> 	} else {
>-		sz = RTE_ALIGN_CEIL(elt_sz, pg_sz) * elt_num;
>+		sz = RTE_ALIGN_CEIL(total_elt_sz, pg_sz) * elt_num;
> 	}
> 
> 	return sz;
>@@ -362,7 +363,7 @@ mempool_lelem_iter(void *arg, __rte_unused void *start, void *end,
>  * given memory footprint to store required number of elements.
>  */
> ssize_t
>-rte_mempool_xmem_usage(void *vaddr, uint32_t elt_num, size_t elt_sz,
>+rte_mempool_xmem_usage(void *vaddr, uint32_t elt_num, size_t total_elt_sz,
> 	const phys_addr_t paddr[], uint32_t pg_num, uint32_t pg_shift)
> {
> 	uint32_t n;
>@@ -373,7 +374,7 @@ rte_mempool_xmem_usage(void *vaddr, uint32_t elt_num, size_t elt_sz,
> 	va = (uintptr_t)vaddr;
> 	uv = va;
> 
>-	if ((n = rte_mempool_obj_iter(vaddr, elt_num, elt_sz, 1,
>+	if ((n = rte_mempool_obj_iter(vaddr, elt_num, total_elt_sz, 1,
> 			paddr, pg_num, pg_shift, mempool_lelem_iter,
> 			&uv)) != elt_num) {
> 		return -(ssize_t)n;
>diff --git a/lib/librte_mempool/rte_mempool.h b/lib/librte_mempool/rte_mempool.h
>index bd78df5..ca4657f 100644
>--- a/lib/librte_mempool/rte_mempool.h
>+++ b/lib/librte_mempool/rte_mempool.h
>@@ -1289,7 +1289,7 @@ struct rte_mempool *rte_mempool_lookup(const char *name);
>  * calculates header, trailer, body and total sizes of the mempool object.
>  *
>  * @param elt_size
>- *   The size of each element.
>+ *   The size of each element, without header and trailer.
>  * @param flags
>  *   The flags used for the mempool creation.
>  *   Consult rte_mempool_create() for more information about possible values.
>@@ -1315,14 +1315,15 @@ uint32_t rte_mempool_calc_obj_size(uint32_t elt_size, uint32_t flags,
>  *
>  * @param elt_num
>  *   Number of elements.
>- * @param elt_sz
>- *   The size of each element.
>+ * @param total_elt_sz
>+ *   The size of each element, including header and trailer, as returned
>+ *   by rte_mempool_calc_obj_size().
>  * @param pg_shift
>  *   LOG2 of the physical pages size.
>  * @return
>  *   Required memory size aligned at page boundary.
>  */
>-size_t rte_mempool_xmem_size(uint32_t elt_num, size_t elt_sz,
>+size_t rte_mempool_xmem_size(uint32_t elt_num, size_t total_elt_sz,
> 	uint32_t pg_shift);
> 
> /**
>@@ -1336,8 +1337,9 @@ size_t rte_mempool_xmem_size(uint32_t elt_num, size_t elt_sz,
>  *   Will be used to store mempool objects.
>  * @param elt_num
>  *   Number of elements.
>- * @param elt_sz
>- *   The size of each element.
>+ * @param total_elt_sz
>+ *   The size of each element, including header and trailer, as returned
>+ *   by rte_mempool_calc_obj_size().
>  * @param paddr
>  *   Array of physical addresses of the pages that comprises given memory
>  *   buffer.
>@@ -1351,8 +1353,9 @@ size_t rte_mempool_xmem_size(uint32_t elt_num, size_t elt_sz,
>  *   buffer is too small, return a negative value whose absolute value
>  *   is the actual number of elements that can be stored in that buffer.
>  */
>-ssize_t rte_mempool_xmem_usage(void *vaddr, uint32_t elt_num, size_t elt_sz,
>-	const phys_addr_t paddr[], uint32_t pg_num, uint32_t pg_shift);
>+ssize_t rte_mempool_xmem_usage(void *vaddr, uint32_t elt_num,
>+	size_t total_elt_sz, const phys_addr_t paddr[], uint32_t pg_num,
>+	uint32_t pg_shift);
> 
> /**
>  * Walk list of all memory pools
>-- 
>2.1.4
>
>


Regards,
Keith