lkml.org 
[lkml]   [2022]   [Jun]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v5 6/9] mm/demotion: Add support for removing node from demotion memory tiers
Date
This patch adds the special string "none" as a supported memtier value
that we can use to remove a specific node from being using as demotion target.

For ex:
:/sys/devices/system/node/node1# cat memtier
1
:/sys/devices/system/node/node1# cat ../../memtier/memtier1/nodelist
1-3
:/sys/devices/system/node/node1# echo none > memtier
:/sys/devices/system/node/node1#
:/sys/devices/system/node/node1# cat memtier
:/sys/devices/system/node/node1# cat ../../memtier/memtier1/nodelist
2-3
:/sys/devices/system/node/node1#

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
---
drivers/base/node.c | 4 ++++
include/linux/memory-tiers.h | 1 +
mm/memory-tiers.c | 18 +++++++++++++++---
3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/drivers/base/node.c b/drivers/base/node.c
index 599ed64d910f..344786290149 100644
--- a/drivers/base/node.c
+++ b/drivers/base/node.c
@@ -582,6 +582,10 @@ static ssize_t memtier_store(struct device *dev,
int node = dev->id;
int ret;

+ if (!strncmp(buf, "none", strlen("none"))) {
+ node_remove_from_memory_tier(node);
+ return count;
+ }
ret = kstrtoul(buf, 10, &tier);
if (ret)
return ret;
diff --git a/include/linux/memory-tiers.h b/include/linux/memory-tiers.h
index adc2cb3bf5f8..79bd8d26feb2 100644
--- a/include/linux/memory-tiers.h
+++ b/include/linux/memory-tiers.h
@@ -17,6 +17,7 @@

extern bool numa_demotion_enabled;
int next_demotion_node(int node);
+void node_remove_from_memory_tier(int node);
int node_get_memory_tier_id(int node);
int node_set_memory_tier(int node, int tier);
int node_reset_memory_tier(int node, int tier);
diff --git a/mm/memory-tiers.c b/mm/memory-tiers.c
index 9c82cf4c4bca..b4e72b672d4d 100644
--- a/mm/memory-tiers.c
+++ b/mm/memory-tiers.c
@@ -253,8 +253,7 @@ static struct memory_tier *__get_memory_tier_from_id(int id)
return NULL;
}

-__maybe_unused // temporay to prevent warnings during bisects
-static void node_remove_from_memory_tier(int node)
+void node_remove_from_memory_tier(int node)
{
struct memory_tier *memtier;

@@ -320,7 +319,20 @@ int node_reset_memory_tier(int node, int tier)
mutex_lock(&memory_tier_lock);

current_tier = __node_get_memory_tier(node);
- if (!current_tier || current_tier->dev.id == tier)
+ if (!current_tier) {
+ /*
+ * If a N_MEMORY node doesn't have a tier index, then
+ * we removed it from demotion earlier and we are trying
+ * add it back. Just add the node to requested tier.
+ */
+ if (node_state(node, N_MEMORY)) {
+ ret = __node_set_memory_tier(node, tier);
+ establish_migration_targets();
+ }
+ goto out;
+ }
+
+ if (current_tier->dev.id == tier)
goto out;

node_clear(node, current_tier->nodelist);
--
2.36.1
\
 
 \ /
  Last update: 2022-06-03 15:45    [W:0.450 / U:1.536 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site