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* [dpdk-dev] [PATCH] doc: add stack mempool guide
@ 2020-08-11 21:10 Gage Eads
  2020-08-24 16:13 ` Gage Eads
                   ` (2 more replies)
  0 siblings, 3 replies; 9+ messages in thread
From: Gage Eads @ 2020-08-11 21:10 UTC (permalink / raw)
  To: dev; +Cc: olivier.matz, arybchenko, john.mcnamara, marko.kovacevic

Signed-off-by: Gage Eads <gage.eads@intel.com>
---
 doc/guides/mempool/index.rst          |  1 +
 doc/guides/mempool/stack.rst          | 38 +++++++++++++++++++++++++++++++++++
 doc/guides/prog_guide/mempool_lib.rst |  2 ++
 doc/guides/prog_guide/stack_lib.rst   |  4 ++++
 4 files changed, 45 insertions(+)
 create mode 100644 doc/guides/mempool/stack.rst

diff --git a/doc/guides/mempool/index.rst b/doc/guides/mempool/index.rst
index bbd02fd81..a0e55467e 100644
--- a/doc/guides/mempool/index.rst
+++ b/doc/guides/mempool/index.rst
@@ -14,3 +14,4 @@ application through the mempool API.
     octeontx
     octeontx2
     ring
+    stack
diff --git a/doc/guides/mempool/stack.rst b/doc/guides/mempool/stack.rst
new file mode 100644
index 000000000..3baa774f3
--- /dev/null
+++ b/doc/guides/mempool/stack.rst
@@ -0,0 +1,38 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2020 Intel Corporation.
+
+Stack Mempool Driver
+===================
+
+**rte_mempool_stack** is a pure software mempool driver based on the
+``rte_stack`` DPDK library. A stack-based mempool is often better suited to
+packet-processing workloads than a ring-based mempool, since its LIFO behavior
+results in better temporal locality and a minimal memory footprint even if the
+mempool is over-provisioned.
+
+The following modes of operation are available for the stack mempool driver and
+can be selected as described in :ref:`Mempool_Handlers`:
+
+- ``stack``
+
+  The underlying **rte_stack** operates in standard (lock-based) mode.
+  For more information please refer to :ref:`Stack_Library_Std_Stack`.
+
+- ``lf_stack``
+
+  The underlying **rte_stack** operates in lock-free mode. For more
+  information please refer to :ref:`Stack_Library_LF_Stack`.
+
+The standard stack outperforms the lock-free stack on average, however the
+standard stack is non-preemptive: if a mempool user is preempted while holding
+the stack lock, that thread will block all other mempool accesses until it
+returns and releases the lock. As a result, an application using the standard
+stack whose threads can be preempted can suffer from brief, infrequent
+performance hiccups.
+
+The lock-free stack, by design, is not susceptible to this problem; one thread can
+be preempted at any point during a push or pop operation and will not impede
+the progress of any other thread.
+
+For a more detailed description of the stack implementations, please refer to
+:doc:`../prog_guide/stack_lib`.
diff --git a/doc/guides/prog_guide/mempool_lib.rst b/doc/guides/prog_guide/mempool_lib.rst
index e3e1f940b..6f3c0067f 100644
--- a/doc/guides/prog_guide/mempool_lib.rst
+++ b/doc/guides/prog_guide/mempool_lib.rst
@@ -105,6 +105,8 @@ These user-owned caches can be explicitly passed to ``rte_mempool_generic_put()`
 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:
+
 Mempool Handlers
 ------------------------
 
diff --git a/doc/guides/prog_guide/stack_lib.rst b/doc/guides/prog_guide/stack_lib.rst
index 8fe8804e3..3097cab0c 100644
--- a/doc/guides/prog_guide/stack_lib.rst
+++ b/doc/guides/prog_guide/stack_lib.rst
@@ -28,6 +28,8 @@ Implementation
 The library supports two types of stacks: standard (lock-based) and lock-free.
 Both types use the same set of interfaces, but their implementations differ.
 
+.. _Stack_Library_Std_Stack:
+
 Lock-based Stack
 ----------------
 
@@ -35,6 +37,8 @@ The lock-based stack consists of a contiguous array of pointers, a current
 index, and a spinlock. Accesses to the stack are made multi-thread safe by the
 spinlock.
 
+.. _Stack_Library_LF_Stack:
+
 Lock-free Stack
 ------------------
 
-- 
2.13.6


^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2020-10-08 10:20 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-08-11 21:10 [dpdk-dev] [PATCH] doc: add stack mempool guide Gage Eads
2020-08-24 16:13 ` Gage Eads
2020-09-14 21:11 ` [dpdk-dev] [PATCH v3] " Gage Eads
2020-09-17 14:25   ` Olivier Matz
2020-09-21 15:42     ` Eads, Gage
2020-10-07  8:43       ` Olivier Matz
2020-10-07 14:18 ` [dpdk-dev] [PATCH v4] " Gage Eads
2020-10-07 14:40   ` Olivier Matz
2020-10-08 10:19     ` David Marchand

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