[PATCH 05/12] mm/mempolicy: refactor rebind code for PREFERRED_MANY

From: Ben Widawsky
Date: Tue Jun 30 2020 - 17:25:56 EST


From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

Again, this extracts the "only one node must be set" behavior of
MPOL_PREFERRED. It retains virtually all of the existing code so it can
be used by MPOL_PREFERRED_MANY as well.

v2:
Fixed typos in commit message. (Ben)
Merged bits from other patches. (Ben)
annotate mpol_rebind_preferred_many as unused (Ben)

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Widawsky <ben.widawsky@xxxxxxxxx>
---
mm/mempolicy.c | 29 ++++++++++++++++++++++-------
1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 1ad6e446d8f6..d320a02fd35b 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -359,14 +359,11 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
pol->v.nodes = tmp;
}

-static void mpol_rebind_preferred(struct mempolicy *pol,
- const nodemask_t *nodes)
+static void mpol_rebind_preferred_common(struct mempolicy *pol,
+ const nodemask_t *preferred_nodes,
+ const nodemask_t *nodes)
{
nodemask_t tmp;
- nodemask_t preferred_node;
-
- /* MPOL_PREFERRED uses only the first node in the mask */
- preferred_node = nodemask_of_node(first_node(*nodes));

if (pol->flags & MPOL_F_STATIC_NODES) {
int node = first_node(pol->w.user_nodemask);
@@ -381,12 +378,30 @@ static void mpol_rebind_preferred(struct mempolicy *pol,
pol->v.preferred_nodes = tmp;
} else if (!(pol->flags & MPOL_F_LOCAL)) {
nodes_remap(tmp, pol->v.preferred_nodes,
- pol->w.cpuset_mems_allowed, preferred_node);
+ pol->w.cpuset_mems_allowed, *preferred_nodes);
pol->v.preferred_nodes = tmp;
pol->w.cpuset_mems_allowed = *nodes;
}
}

+/* MPOL_PREFERRED_MANY allows multiple nodes to be set in 'nodes' */
+static void __maybe_unused mpol_rebind_preferred_many(struct mempolicy *pol,
+ const nodemask_t *nodes)
+{
+ mpol_rebind_preferred_common(pol, nodes, nodes);
+}
+
+static void mpol_rebind_preferred(struct mempolicy *pol,
+ const nodemask_t *nodes)
+{
+ nodemask_t preferred_node;
+
+ /* MPOL_PREFERRED uses only the first node in 'nodes' */
+ preferred_node = nodemask_of_node(first_node(*nodes));
+
+ mpol_rebind_preferred_common(pol, &preferred_node, nodes);
+}
+
/*
* mpol_rebind_policy - Migrate a policy to a different set of nodes
*
--
2.27.0