[PATCH bpf-next v5 1/2] docs/bpf: Add table to describe LRU properties

From: Joe Stringer
Date: Sat Apr 22 2023 - 13:21:09 EST


Depending on the map type and flags for LRU, different properties are
global or percpu. Add a table to describe these.

Signed-off-by: Joe Stringer <joe@xxxxxxxxxxxxx>
---
v5: Use bold rather than verbatim for column header
v4: Initial posting
---
Documentation/bpf/map_hash.rst | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/Documentation/bpf/map_hash.rst b/Documentation/bpf/map_hash.rst
index 8669426264c6..1314dfc5e7e1 100644
--- a/Documentation/bpf/map_hash.rst
+++ b/Documentation/bpf/map_hash.rst
@@ -29,7 +29,16 @@ will automatically evict the least recently used entries when the hash
table reaches capacity. An LRU hash maintains an internal LRU list that
is used to select elements for eviction. This internal LRU list is
shared across CPUs but it is possible to request a per CPU LRU list with
-the ``BPF_F_NO_COMMON_LRU`` flag when calling ``bpf_map_create``.
+the ``BPF_F_NO_COMMON_LRU`` flag when calling ``bpf_map_create``. The
+following table outlines the properties of LRU maps depending on the a
+map type and the flags used to create the map.
+
+======================== ========================= ================================
+Flag ``BPF_MAP_TYPE_LRU_HASH`` ``BPF_MAP_TYPE_LRU_PERCPU_HASH``
+======================== ========================= ================================
+**BPF_F_NO_COMMON_LRU** Per-CPU LRU, global map Per-CPU LRU, per-cpu map
+**!BPF_F_NO_COMMON_LRU** Global LRU, global map Global LRU, per-cpu map
+======================== ========================= ================================

Usage
=====
--
2.34.1