[dpdk-dev] [PATCH v3 2/4] mempool: add non-IO flag

[Dmitry Kozlyuk <dkozlyuk@oss.nvidia.com>]

Mempool is a generic allocator that is not necessarily used for device
IO operations and its memory for DMA. Add MEMPOOL_F_NON_IO flag to mark
such mempools.
Discussion: https://mails.dpdk.org/archives/dev/2021-August/216654.html

Signed-off-by: Dmitry Kozlyuk <dkozlyuk@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>
---
 doc/guides/rel_notes/release_21_11.rst | 3 +++
 lib/mempool/rte_mempool.h              | 4 ++++
 2 files changed, 7 insertions(+)

diff --git a/doc/guides/rel_notes/release_21_11.rst b/doc/guides/rel_notes/release_21_11.rst
index 5036641842..dbabdc9759 100644
--- a/doc/guides/rel_notes/release_21_11.rst
+++ b/doc/guides/rel_notes/release_21_11.rst
@@ -208,6 +208,9 @@ API Changes
   the crypto/security operation. This field will be used to communicate
   events such as soft expiry with IPsec in lookaside mode.
 
+* mempool: Added ``MEMPOOL_F_NON_IO`` flag to give a hint to DPDK components
+  that objects from this pool will not be used for device IO (e.g. DMA).
+
 
 ABI Changes
 -----------
diff --git a/lib/mempool/rte_mempool.h b/lib/mempool/rte_mempool.h
index e2bf40aa09..b48d9f89c2 100644
--- a/lib/mempool/rte_mempool.h
+++ b/lib/mempool/rte_mempool.h
@@ -262,6 +262,7 @@ struct rte_mempool {
 #define MEMPOOL_F_SC_GET         0x0008 /**< Default get is "single-consumer".*/
 #define MEMPOOL_F_POOL_CREATED   0x0010 /**< Internal: pool is created. */
 #define MEMPOOL_F_NO_IOVA_CONTIG 0x0020 /**< Don't need IOVA contiguous objs. */
+#define MEMPOOL_F_NON_IO         0x0040 /**< Not used for device IO (DMA). */
 
 /**
  * @internal When debug is enabled, store some statistics.
@@ -991,6 +992,9 @@ typedef void (rte_mempool_ctor_t)(struct rte_mempool *, void *);
  *     "single-consumer". Otherwise, it is "multi-consumers".
  *   - MEMPOOL_F_NO_IOVA_CONTIG: If set, allocated objects won't
  *     necessarily be contiguous in IO memory.
+ *   - MEMPOOL_F_NON_IO: If set, the mempool is considered to be
+ *     never used for device IO, i.e. for DMA operations.
+ *     It's a hint to other components and does not affect the mempool behavior.
  * @return
  *   The pointer to the new allocated mempool, on success. NULL on error
  *   with rte_errno set appropriately. Possible rte_errno values include:
-- 
2.25.1