linux-gen: ishm: internal shared memory allocator (ishm) added

A new ODP internal memory allocator, called ishm (for internal shmem)
is introduced here.
This memory allocator enables the following:
- works for odpthreads being linux processes, regardless for fork time.
- guarantees the uniqueness of the virtual space mapping address over
all ODP threads (even processes and regardless of fork time),
when the required _ODP_ISHM_SINGLE_VA flag is used.

Signed-off-by: Christophe Milard <christophe.milard@linaro.org>
Reviewed-and-tested-by: Bill Fischofer <bill.fischofer@linaro.org>
Reviewed-by: Brian Brooks <brian.brooks@linaro.org>
Signed-off-by: Maxim Uvarov <maxim.uvarov@linaro.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/platform/linux-generic/include/odp_config_internal.h b/platform/linux-generic/include/odp_config_internal.h
index 06550e6a1..e89a6a3bc 100644
--- a/platform/linux-generic/include/odp_config_internal.h
+++ b/platform/linux-generic/include/odp_config_internal.h
@@ -124,6 +124,16 @@ extern "C" {
  */
 #define CONFIG_POOL_CACHE_SIZE 256
 
+/*
+ * Size of the virtual address space pre-reserver for ISHM
+ *
+ * This is just virtual space preallocation size, not memory allocation.
+ * This address space is used by ISHM to map things at a common address in
+ * all ODP threads (when the _ODP_ISHM_SINGLE_VA flag is used).
+ * In bytes.
+ */
+#define ODP_CONFIG_ISHM_VA_PREALLOC_SZ (536870912L)
+
 #ifdef __cplusplus
 }
 #endif