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From:   Jagdish Gediya <jvgediya@linux.ibm.com>
To:     linux-mm@kvack.org, linux-kernel@vger.kernel.org
Cc:     akpm@linux-foundation.org, aneesh.kumar@linux.ibm.com,
        baolin.wang@linux.alibaba.com, dave.hansen@linux.intel.com,
        ying.huang@intel.com, Jagdish Gediya <jvgediya@linux.ibm.com>
Subject: [PATCH v2 2/5] mm: demotion: Add new node state N_DEMOTION_TARGETS
Date:   Wed, 13 Apr 2022 14:52:03 +0530
Message-Id: <20220413092206.73974-3-jvgediya@linux.ibm.com>
In-Reply-To: <20220413092206.73974-1-jvgediya@linux.ibm.com>
References: <20220413092206.73974-1-jvgediya@linux.ibm.com>
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Current implementation to find the demotion targets works
based on node state N_MEMORY, however some systems may have
dram only memory numa node which are N_MEMORY but not the
right choices as demotion targets.

Add new state N_DEMOTION_TARGETS, node_states[N_DEMOTION_TARGETS]
then can be used to hold the list of nodes which can be used
as demotion targets.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Jagdish Gediya <jvgediya@linux.ibm.com>
---
 drivers/base/node.c      | 4 ++++
 include/linux/nodemask.h | 1 +
 2 files changed, 5 insertions(+)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index ec8bb24a5a22..cd79815b0f7a 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -1038,6 +1038,9 @@ static struct node_attr node_state_attr[] = {
 	[N_CPU] = _NODE_ATTR(has_cpu, N_CPU),
 	[N_GENERIC_INITIATOR] = _NODE_ATTR(has_generic_initiator,
 					   N_GENERIC_INITIATOR),
+	[N_DEMOTION_TARGETS] = _NODE_ATTR(has_demotion_targets,
+					  N_DEMOTION_TARGETS),
+
 };
 
 static struct attribute *node_state_attrs[] = {
@@ -1050,6 +1053,7 @@ static struct attribute *node_state_attrs[] = {
 	&node_state_attr[N_MEMORY].attr.attr,
 	&node_state_attr[N_CPU].attr.attr,
 	&node_state_attr[N_GENERIC_INITIATOR].attr.attr,
+	&node_state_attr[N_DEMOTION_TARGETS].attr.attr,
 	NULL
 };
 
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 567c3ddba2c4..17844300fd57 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -400,6 +400,7 @@ enum node_states {
 	N_MEMORY,		/* The node has memory(regular, high, movable) */
 	N_CPU,		/* The node has one or more cpus */
 	N_GENERIC_INITIATOR,	/* The node has one or more Generic Initiators */
+	N_DEMOTION_TARGETS,	/* Nodes that should be considered as demotion targets */
 	NR_NODE_STATES
 };
 
-- 
2.35.1