[dpdk-dev] [PATCH 2/2] memzone: allow IOVA-contiguous memzones with zero size

[Anatoly Burakov]

Previously, reserving IOVA-contiguous memzones with zero
size (which would reserve biggest available memzone) was
not allowed. Now that we can have biggest IOVA-contiguous
malloc element statistic exposed through a malloc stats
call, this now becomes possible.

Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
---
 lib/librte_eal/common/eal_common_memzone.c | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_memzone.c 
b/lib/librte_eal/common/eal_common_memzone.c
index bce3321..22b60b5 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -57,7 +57,7 @@ memzone_lookup_thread_unsafe(const char *name)
  * specified. If no heap has been specified, it will return the heap and
  * length of the greatest free block available in all heaps */
 static size_t
-find_heap_max_free_elem(int *s, unsigned align)
+find_heap_max_free_elem(int *s, unsigned align, bool contig)
 {
        struct rte_mem_config *mcfg;
        struct rte_malloc_socket_stats stats;
@@ -68,12 +68,16 @@ find_heap_max_free_elem(int *s, unsigned align)
        mcfg = rte_eal_get_configuration()->mem_config;
 
        for (i = 0; i < RTE_MAX_NUMA_NODES; i++) {
+               size_t found_len;
                if ((socket != SOCKET_ID_ANY) && (socket != i))
                        continue;
 
                malloc_heap_get_stats(&mcfg->malloc_heaps[i], &stats);
-               if (stats.greatest_free_size > len) {
-                       len = stats.greatest_free_size;
+               found_len = contig ?
+                               stats.greatest_free_iova_contig_size :
+                               stats.greatest_free_size;
+               if (found_len > len) {
+                       len = found_len;
                        *s = i;
                }
        }
@@ -166,16 +170,11 @@ memzone_reserve_aligned_thread_unsafe(const char *name, 
size_t len,
        flags &= ~RTE_MEMZONE_IOVA_CONTIG;
 
        if (len == 0) {
-               /* len == 0 is only allowed for non-contiguous zones */
-               if (contig) {
-                       RTE_LOG(DEBUG, EAL, "Reserving zero-length contiguous 
memzones is not supported\n");
-                       rte_errno = EINVAL;
-                       return NULL;
-               }
                if (bound != 0)
                        requested_len = bound;
                else {
-                       requested_len = find_heap_max_free_elem(&socket_id, 
align);
+                       requested_len = find_heap_max_free_elem(&socket_id,
+                                       align, contig);
                        if (requested_len == 0) {
                                rte_errno = ENOMEM;
                                return NULL;
-- 
2.7.4