common/mlx5: fix aligned malloc

Before this commit system call memalign was used for aligned
allocations, however memalign is deprecated.

Based on (1) - POSIX requires that memory aligned allocations can be
freed using free. Some systems provide no way to reclaim memory
allocated with memalign (because one can only pass to free a pointer
gotten from malloc, while, memalign would call malloc and then align the
obtained value).
Another issue is that 64/32 bits architectures use a minimal alignment
size. So any requested alignment below the minimal system size can be
simplified by calling malloc.

The glibc implementation allows memory obtained from posix_memalign to
be reclaimed with free.  This commit replaces system call memalign with
system call posix_memalign. It also calls malloc in case the requested
alignment is below the minimal system size.

(1) https://linux.die.net/man/3/memalign

Fixes: d38e3d526657 ("common/mlx5: add memory management functions")
Cc: stable@dpdk.org
Signed-off-by: Ophir Munk <ophirmu@nvidia.com>
Acked-by: Matan Azrad <matan@mellanox.com>

diff --git a/drivers/common/mlx5/mlx5_malloc.c b/drivers/common/mlx5/mlx5_malloc.c
index 316305d..4489971 100644 (file)
--- a/drivers/common/mlx5/mlx5_malloc.c
+++ b/drivers/common/mlx5/mlx5_malloc.c
@@ -151,9 +151,14 @@ static void *
 mlx5_alloc_align(size_t size, unsigned int align, unsigned int zero)
 {
        void *buf;
-       buf = memalign(align, size);
-       if (!buf) {
-               DRV_LOG(ERR, "Couldn't allocate buf.\n");
+       int ret;
+
+       ret = posix_memalign(&buf, align, size);
+       if (ret) {
+               DRV_LOG(ERR,
+                       "Couldn't allocate buf size=%zu align=%u. Err=%d\n",
+                       size, align, ret);
+
                return NULL;
        }
        if (zero)
@@ -190,7 +195,7 @@ mlx5_malloc(uint32_t flags, size_t size, unsigned int align, int socket)
                return addr;
        }
        /* The memory will be allocated from system. */
-       if (align)
+       if (align > MLX5_MALLOC_ALIGNMENT)
                addr = mlx5_alloc_align(size, align, !!(flags & MLX5_MEM_ZERO));
        else if (flags & MLX5_MEM_ZERO)
                addr = calloc(1, size);

diff --git a/drivers/common/mlx5/mlx5_malloc.h b/drivers/common/mlx5/mlx5_malloc.h
index d3e5f5b..8aea414 100644 (file)
--- a/drivers/common/mlx5/mlx5_malloc.h
+++ b/drivers/common/mlx5/mlx5_malloc.h
@@ -9,6 +9,14 @@
 extern "C" {
 #endif
 
+#ifndef MLX5_MALLOC_ALIGNMENT
+#ifndef RTE_ARCH_64
+#define MLX5_MALLOC_ALIGNMENT 8
+#else
+#define MLX5_MALLOC_ALIGNMENT 16
+#endif
+#endif
+
 enum mlx5_mem_flags {
        MLX5_MEM_ANY = 0,
        /* Memory will be allocated dpends on sys_mem_en. */