* [PATCH v2] kernfs: Allocating memory for kernfs_iattrs with kmem_cache.
[not found] <CGME20190206050507epcas5p30ea6ad0f13693aeacbf41088d2c380a5@epcas5p3.samsung.com>
@ 2019-02-06 4:55 ` Ayush Mittal
2019-02-06 16:35 ` Tejun Heo
0 siblings, 1 reply; 2+ messages in thread
From: Ayush Mittal @ 2019-02-06 4:55 UTC (permalink / raw)
To: gregkh, tj, linux-kernel; +Cc: pankaj.m, a.sahrawat, v.narang, Ayush Mittal
Creating a new cache for kernfs_iattrs.
Currently, memory is allocated with kzalloc() which
always gives aligned memory. On ARM, this is 64 byte aligned.
To avoid the wastage of memory in aligning the size requested,
a new cache for kernfs_iattrs is created.
Size of struct kernfs_iattrs is 80 Bytes.
On ARM, it will come in kmalloc-128 slab.
and it will come in kmalloc-192 slab if debug info is enabled.
Extra bytes taken 48 bytes.
Total number of objects created : 4096
Total saving = 48*4096 = 192 KB
After creating new slab(When debug info is enabled) :
sh-3.2# cat /proc/slabinfo
...
kernfs_iattrs_cache 4069 4096 128 32 1 : tunables 0 0 0 : slabdata 128 128 0
...
All testing has been done on ARM target.
Signed-off-by: Ayush Mittal <ayush.m@samsung.com>
Signed-off-by: Vaneet Narang <v.narang@samsung.com>
---
v1 -> v2: Changed slab creation flag.
fs/kernfs/dir.c | 2 +-
fs/kernfs/inode.c | 2 +-
fs/kernfs/kernfs-internal.h | 2 +-
fs/kernfs/mount.c | 7 ++++++-
4 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 4ca0b5c..b84d635 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -536,8 +536,8 @@ void kernfs_put(struct kernfs_node *kn)
security_release_secctx(kn->iattr->ia_secdata,
kn->iattr->ia_secdata_len);
simple_xattrs_free(&kn->iattr->xattrs);
+ kmem_cache_free(kernfs_iattrs_cache, kn->iattr);
}
- kfree(kn->iattr);
spin_lock(&kernfs_idr_lock);
idr_remove(&root->ino_idr, kn->id.ino);
spin_unlock(&kernfs_idr_lock);
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 80cebcd..0c1fd94 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -42,7 +42,7 @@ static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
if (kn->iattr)
goto out_unlock;
- kn->iattr = kzalloc(sizeof(struct kernfs_iattrs), GFP_KERNEL);
+ kn->iattr = kmem_cache_zalloc(kernfs_iattrs_cache, GFP_KERNEL);
if (!kn->iattr)
goto out_unlock;
iattrs = &kn->iattr->ia_iattr;
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 3d83b11..dba810c 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -78,7 +78,7 @@ static inline struct kernfs_node *kernfs_dentry_node(struct dentry *dentry)
}
extern const struct super_operations kernfs_sops;
-extern struct kmem_cache *kernfs_node_cache;
+extern struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
/*
* inode.c
diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index fdf527b..450eb38 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -20,7 +20,7 @@
#include "kernfs-internal.h"
-struct kmem_cache *kernfs_node_cache;
+struct kmem_cache *kernfs_node_cache, *kernfs_iattrs_cache;
static int kernfs_sop_remount_fs(struct super_block *sb, int *flags, char *data)
{
@@ -417,4 +417,9 @@ void __init kernfs_init(void)
0,
SLAB_PANIC | SLAB_TYPESAFE_BY_RCU,
NULL);
+
+ /* Creates slab cache for kernfs inode attributes */
+ kernfs_iattrs_cache = kmem_cache_create("kernfs_iattrs_cache",
+ sizeof(struct kernfs_iattrs),
+ 0, SLAB_PANIC, NULL);
}
--
1.9.1
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