eal: register non-EAL threads as lcores

[dpdk.git] / doc / guides / prog_guide / mempool_lib.rst

diff --git a/doc/guides/prog_guide/mempool_lib.rst b/doc/guides/prog_guide/mempool_lib.rst
index 1943fc4..e3e1f94 100644 (file)
--- a/doc/guides/prog_guide/mempool_lib.rst
+++ b/doc/guides/prog_guide/mempool_lib.rst
@@ -1,32 +1,5 @@
-..  BSD LICENSE
-    Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
-    All rights reserved.
-
-    Redistribution and use in source and binary forms, with or without
-    modification, are permitted provided that the following conditions
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-
-    * Redistributions of source code must retain the above copyright
-    notice, this list of conditions and the following disclaimer.
-    * Redistributions in binary form must reproduce the above copyright
-    notice, this list of conditions and the following disclaimer in
-    the documentation and/or other materials provided with the
-    distribution.
-    * Neither the name of Intel Corporation nor the names of its
-    contributors may be used to endorse or promote products derived
-    from this software without specific prior written permission.
-
-    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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-    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2010-2014 Intel Corporation.
 
 .. _Mempool_Library:
 
@@ -54,10 +27,10 @@ In debug mode (CONFIG_RTE_LIBRTE_MEMPOOL_DEBUG is enabled),
 statistics about get from/put in the pool are stored in the mempool structure.
 Statistics are per-lcore to avoid concurrent access to statistics counters.
 
-Memory Alignment Constraints
-----------------------------
+Memory Alignment Constraints on x86 architecture
+------------------------------------------------
 
-Depending on hardware memory configuration, performance can be greatly improved by adding a specific padding between objects.
+Depending on hardware memory configuration on X86 architecture, performance can be greatly improved by adding a specific padding between objects.
 The objective is to ensure that the beginning of each object starts on a different channel and rank in memory so that all channels are equally loaded.
 
 This is particularly true for packet buffers when doing L3 forwarding or flow classification.
@@ -115,7 +88,7 @@ While this may mean a number of buffers may sit idle on some core's cache,
 the speed at which a core can access its own cache for a specific memory pool without locks provides performance gains.
 
 The cache is composed of a small, per-core table of pointers and its length (used as a stack).
-This cache can be enabled or disabled at creation of the pool.
+This internal cache can be enabled or disabled at creation of the pool.
 
 The maximum size of the cache is static and is defined at compilation time (CONFIG_RTE_MEMPOOL_CACHE_MAX_SIZE).
 
@@ -127,6 +100,10 @@ The maximum size of the cache is static and is defined at compilation time (CONF
 
    A mempool in Memory with its Associated Ring
 
+Alternatively to the internal default per-lcore local cache, an application can create and manage external caches through the ``rte_mempool_cache_create()``, ``rte_mempool_cache_free()`` and ``rte_mempool_cache_flush()`` calls.
+These user-owned caches can be explicitly passed to ``rte_mempool_generic_put()`` and ``rte_mempool_generic_get()``.
+The ``rte_mempool_default_cache()`` call returns the default internal cache if any.
+In contrast to the default caches, user-owned caches can be used by unregistered non-EAL threads too.
 
 Mempool Handlers
 ------------------------
@@ -137,7 +114,7 @@ management systems and software based memory allocators, to be used with DPDK.
 There are two aspects to a mempool handler.
 
 * Adding the code for your new mempool operations (ops). This is achieved by
-  adding a new mempool ops code, and using the ``REGISTER_MEMPOOL_OPS`` macro.
+  adding a new mempool ops code, and using the ``MEMPOOL_REGISTER_OPS`` macro.
 
 * Using the new API to call ``rte_mempool_create_empty()`` and
   ``rte_mempool_set_ops_byname()`` to create a new mempool and specifying which
@@ -156,6 +133,14 @@ For applications that use ``rte_pktmbuf_create()``, there is a config setting
 (``RTE_MBUF_DEFAULT_MEMPOOL_OPS``) that allows the application to make use of
 an alternative mempool handler.
 
+  .. note::
+
+    When running a DPDK application with shared libraries, mempool handler
+    shared objects specified with the '-d' EAL command-line parameter are
+    dynamically loaded. When running a multi-process application with shared
+    libraries, the -d arguments for mempool handlers *must be specified in the
+    same order for all processes* to ensure correct operation.
+
 
 Use Cases
 ---------