[dpdk-dev] [PATCH 1/2] eal/malloc: merge malloc_elems in heap if they are contiguous

[Gowrishankar]

From: Gowrishankar Muthukrishnan <gowrishanka...@linux.vnet.ibm.com>

During malloc heap init, if there are malloc_elems contiguous in
virt addresses, they could be merged so that, merged malloc_elem
would guarantee larger free memory size than its actual hugepage
size, it was created for.

Fixes: fafcc11985 ("mem: rework memzone to be allocated by malloc")
Cc: sta...@dpdk.org

Signed-off-by: Gowrishankar Muthukrishnan <gowrishanka...@linux.vnet.ibm.com>
---
 lib/librte_eal/common/malloc_heap.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/lib/librte_eal/common/malloc_heap.c 
b/lib/librte_eal/common/malloc_heap.c
index 267a4c6..1cacf7f 100644
--- a/lib/librte_eal/common/malloc_heap.c
+++ b/lib/librte_eal/common/malloc_heap.c
@@ -213,7 +213,9 @@
 {
        struct rte_mem_config *mcfg = rte_eal_get_configuration()->mem_config;
        unsigned ms_cnt;
-       struct rte_memseg *ms;
+       struct rte_memseg *ms, *prev_ms = NULL;
+       struct malloc_elem *elem, *prev_elem;
+       int ret;
 
        if (mcfg == NULL)
                return -1;
@@ -222,6 +224,32 @@
                        (ms_cnt < RTE_MAX_MEMSEG) && (ms->len > 0);
                        ms_cnt++, ms++) {
                malloc_heap_add_memseg(&mcfg->malloc_heaps[ms->socket_id], ms);
+               elem = (struct malloc_elem *)ms->addr;
+               if (prev_ms != NULL && \
+                       (ms->socket_id == prev_ms->socket_id)) {
+                       prev_elem = (struct malloc_elem *)prev_ms->addr;
+
+                       /* prev_elem and elem to be contiguous for the resize.
+                          Other wise look for prev_elem in iterations */
+                       if (elem != RTE_PTR_ADD(prev_elem,
+                               prev_elem->size + MALLOC_ELEM_OVERHEAD)) {
+                               prev_ms = ms;
+                               continue;
+                       }
+                       /* end BUSY elem pointed by prev_elem can be merged
+                          with prev_elem itself, as it expands it size now.
+                        */
+                       prev_elem->size += MALLOC_ELEM_OVERHEAD;
+
+                       /* preserve end BUSY elem that points to current elem,
+                          or else free_list will be broken */
+                       ret = malloc_elem_resize(prev_elem,
+                               prev_elem->size + elem->size - 
MALLOC_ELEM_OVERHEAD);
+                       if (ret < 0)
+                               prev_elem = elem;
+               } else {
+                       prev_ms = ms;
+               }
        }
 
        return 0;
-- 
1.9.1