We currently use a compile-time constant to size the node array for the
list_lru structure. Due to this, we don't need to allocate any memory at
initialization time. But as a consequence, the structures that contain
embedded list_lru lists can become way too big (the superblock for
instance contains two of them).
This patch aims at ameliorating this situation by dynamically allocating
the node arrays with the firmware provided nr_node_ids.
Signed-off-by: Glauber Costa <glommer@xxxxxxxxxx>
Cc: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
---
fs/super.c | 11 +++++++++--
fs/xfs/xfs_buf.c | 6 +++++-
fs/xfs/xfs_qm.c | 10 ++++++++--
include/linux/list_lru.h | 13 ++-----------
mm/list_lru.c | 14 +++++++++++++-
5 files changed, 37 insertions(+), 17 deletions(-)
diff --git a/fs/super.c b/fs/super.c
index 85a6104..1b6ef7b 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -199,8 +199,12 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
INIT_HLIST_NODE(&s->s_instances);
INIT_HLIST_BL_HEAD(&s->s_anon);
INIT_LIST_HEAD(&s->s_inodes);
- list_lru_init(&s->s_dentry_lru);
- list_lru_init(&s->s_inode_lru);
+
+ if (list_lru_init(&s->s_dentry_lru))
+ goto err_out;
+ if (list_lru_init(&s->s_inode_lru))
+ goto err_out_dentry_lru;
+
INIT_LIST_HEAD(&s->s_mounts);
init_rwsem(&s->s_umount);
lockdep_set_class(&s->s_umount, &type->s_umount_key);
@@ -240,6 +244,9 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
}
out:
return s;
+
+err_out_dentry_lru:
+ list_lru_destroy(&s->s_dentry_lru);
err_out:
security_sb_free(s);
#ifdef CONFIG_SMP
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index c3f8ea9..9c2b656 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1591,6 +1591,7 @@ xfs_free_buftarg(
struct xfs_mount *mp,
struct xfs_buftarg *btp)
{
+ list_lru_destroy(&btp->bt_lru);
unregister_shrinker(&btp->bt_shrinker);
if (mp->m_flags & XFS_MOUNT_BARRIER)
@@ -1665,9 +1666,12 @@ xfs_alloc_buftarg(
if (!btp->bt_bdi)
goto error;
- list_lru_init(&btp->bt_lru);
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;
+
+ if (list_lru_init(&btp->bt_lru))
+ goto error;
+
btp->bt_shrinker.count_objects = xfs_buftarg_shrink_count;
btp->bt_shrinker.scan_objects = xfs_buftarg_shrink_scan;
btp->bt_shrinker.seeks = DEFAULT_SEEKS;
diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index bd6c12a..b840000 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -781,11 +781,18 @@ xfs_qm_init_quotainfo(
qinf = mp->m_quotainfo = kmem_zalloc(sizeof(xfs_quotainfo_t), KM_SLEEP);
+ if ((error = list_lru_init(&qinf->qi_lru))) {
+ kmem_free(qinf);
+ mp->m_quotainfo = NULL;
+ return error;
+ }
+
/*
* See if quotainodes are setup, and if not, allocate them,
* and change the superblock accordingly.
*/
if ((error = xfs_qm_init_quotainos(mp))) {
+ list_lru_destroy(&qinf->qi_lru);
kmem_free(qinf);
mp->m_quotainfo = NULL;
return error;
@@ -795,8 +802,6 @@ xfs_qm_init_quotainfo(
INIT_RADIX_TREE(&qinf->qi_gquota_tree, GFP_NOFS);
mutex_init(&qinf->qi_tree_lock);
- list_lru_init(&qinf->qi_lru);
-
/* mutex used to serialize quotaoffs */
mutex_init(&qinf->qi_quotaofflock);
@@ -884,6 +889,7 @@ xfs_qm_destroy_quotainfo(
qi = mp->m_quotainfo;
ASSERT(qi != NULL);
+ list_lru_destroy(&qi->qi_lru);
unregister_shrinker(&qi->qi_shrinker);
if (qi->qi_uquotaip) {
diff --git a/include/linux/list_lru.h b/include/linux/list_lru.h
index 2fe13e1..ff57503 100644
--- a/include/linux/list_lru.h
+++ b/include/linux/list_lru.h
@@ -27,20 +27,11 @@ struct list_lru_node {
} ____cacheline_aligned_in_smp;
struct list_lru {
- /*
- * Because we use a fixed-size array, this struct can be very big if
- * MAX_NUMNODES is big. If this becomes a problem this is fixable by
- * turning this into a pointer and dynamically allocating this to
- * nr_node_ids. This quantity is firwmare-provided, and still would
- * provide room for all nodes at the cost of a pointer lookup and an
- * extra allocation. Because that allocation will most likely come from
- * a different slab cache than the main structure holding this
- * structure, we may very well fail.
- */
- struct list_lru_node node[MAX_NUMNODES];
+ struct list_lru_node *node;
nodemask_t active_nodes;
};
+void list_lru_destroy(struct list_lru *lru);
int list_lru_init(struct list_lru *lru);
/**
diff --git a/mm/list_lru.c b/mm/list_lru.c
index 2822817..700d322 100644
--- a/mm/list_lru.c
+++ b/mm/list_lru.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
+#include <linux/slab.h>
bool list_lru_add(struct list_lru *lru, struct list_head *item)
{
@@ -162,9 +163,14 @@ unsigned long list_lru_dispose_all(struct list_lru *lru,
int list_lru_init(struct list_lru *lru)
{
int i;
+ size_t size = sizeof(*lru->node) * nr_node_ids;
+
+ lru->node = kzalloc(size, GFP_KERNEL);
+ if (!lru->node)
+ return -ENOMEM;
nodes_clear(lru->active_nodes);
- for (i = 0; i < MAX_NUMNODES; i++) {
+ for (i = 0; i < nr_node_ids; i++) {
spin_lock_init(&lru->node[i].lock);
INIT_LIST_HEAD(&lru->node[i].list);
lru->node[i].nr_items = 0;
@@ -172,3 +178,9 @@ int list_lru_init(struct list_lru *lru)
return 0;
}
EXPORT_SYMBOL_GPL(list_lru_init);
+
+void list_lru_destroy(struct list_lru *lru)
+{
+ kfree(lru->node);
+}
+EXPORT_SYMBOL_GPL(list_lru_destroy);
--
1.8.1.4
--
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