diff mbox series

doc: add stack mempool guide

Message ID 20200811211015.29704-1-gage.eads@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers show
Series doc: add stack mempool guide | expand


Context Check Description
ci/Intel-compilation success Compilation OK
ci/checkpatch warning coding style issues

Commit Message

Eads, Gage Aug. 11, 2020, 9:10 p.m. UTC
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 mbox series


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.
+    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
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
+.. _Stack_Library_LF_Stack:
 Lock-free Stack