From: Vlastimil Babka <vbabka@xxxxxxx>
Subject: dcache: allocate external names from reclaimable kmalloc caches
We can use the newly introduced kmalloc-reclaimable-X caches, to allocate
external names in dcache, which will take care of the proper accounting
automatically, and also improve anti-fragmentation page grouping.
This effectively reverts commit f1782c9bc547 ("dcache: account external
names as indirectly reclaimable memory") and instead passes
__GFP_RECLAIMABLE to kmalloc(). The accounting thus moves from
NR_INDIRECTLY_RECLAIMABLE_BYTES to NR_SLAB_RECLAIMABLE, which is also
considered in MemAvailable calculation and overcommit decisions.
Link: http://lkml.kernel.org/r/20180731090649.16028-4-vbabka@xxxxxxx
Signed-off-by: Vlastimil Babka <vbabka@xxxxxxx>
Acked-by: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Acked-by: Roman Gushchin <guro@xxxxxx>
Cc: Christoph Lameter <cl@xxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Laura Abbott <labbott@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Sumit Semwal <sumit.semwal@xxxxxxxxxx>
Cc: Vijayanand Jitta <vjitta@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/dcache.c | 38 +++++++++-----------------------------
1 file changed, 9 insertions(+), 29 deletions(-)
--- a/fs/dcache.c~dcache-allocate-external-names-from-reclaimable-kmalloc-caches
+++ a/fs/dcache.c
@@ -257,24 +257,10 @@ static void __d_free(struct rcu_head *he
kmem_cache_free(dentry_cache, dentry);
}
-static void __d_free_external_name(struct rcu_head *head)
-{
- struct external_name *name = container_of(head, struct external_name,
- u.head);
-
- mod_node_page_state(page_pgdat(virt_to_page(name)),
- NR_INDIRECTLY_RECLAIMABLE_BYTES,
- -ksize(name));
-
- kfree(name);
-}
-
static void __d_free_external(struct rcu_head *head)
{
struct dentry *dentry = container_of(head, struct dentry, d_u.d_rcu);
-
- __d_free_external_name(&external_name(dentry)->u.head);
-
+ kfree(external_name(dentry));
kmem_cache_free(dentry_cache, dentry);
}
@@ -306,7 +292,7 @@ void release_dentry_name_snapshot(struct
struct external_name *p;
p = container_of(name->name, struct external_name, name[0]);
if (unlikely(atomic_dec_and_test(&p->u.count)))
- call_rcu(&p->u.head, __d_free_external_name);
+ kfree_rcu(p, u.head);
}
}
EXPORT_SYMBOL(release_dentry_name_snapshot);
@@ -1606,7 +1592,6 @@ EXPORT_SYMBOL(d_invalidate);
struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
{
- struct external_name *ext = NULL;
struct dentry *dentry;
char *dname;
int err;
@@ -1627,14 +1612,15 @@ struct dentry *__d_alloc(struct super_bl
dname = dentry->d_iname;
} else if (name->len > DNAME_INLINE_LEN-1) {
size_t size = offsetof(struct external_name, name[1]);
-
- ext = kmalloc(size + name->len, GFP_KERNEL_ACCOUNT);
- if (!ext) {
+ struct external_name *p = kmalloc(size + name->len,
+ GFP_KERNEL_ACCOUNT |
+ __GFP_RECLAIMABLE);
+ if (!p) {
kmem_cache_free(dentry_cache, dentry);
return NULL;
}
- atomic_set(&ext->u.count, 1);
- dname = ext->name;
+ atomic_set(&p->u.count, 1);
+ dname = p->name;
} else {
dname = dentry->d_iname;
}
@@ -1673,12 +1659,6 @@ struct dentry *__d_alloc(struct super_bl
}
}
- if (unlikely(ext)) {
- pg_data_t *pgdat = page_pgdat(virt_to_page(ext));
- mod_node_page_state(pgdat, NR_INDIRECTLY_RECLAIMABLE_BYTES,
- ksize(ext));
- }
-
this_cpu_inc(nr_dentry);
return dentry;
@@ -2707,7 +2687,7 @@ static void copy_name(struct dentry *den
dentry->d_name.hash_len = target->d_name.hash_len;
}
if (old_name && likely(atomic_dec_and_test(&old_name->u.count)))
- call_rcu(&old_name->u.head, __d_free_external_name);
+ kfree_rcu(old_name, u.head);
}
/*
_
