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authorChao Yu <chao2.yu@samsung.com>2014-12-18 12:37:21 +0300
committerJaegeuk Kim <jaegeuk@kernel.org>2015-01-10 04:02:23 +0300
commit5c27f4ee447b4ef1cd88d5313eeb838c56265571 (patch)
tree4751969bf674317d57582deb6a59dda23f75f2a1 /fs/f2fs/node.h
parent3fa06d7bc9f579bd180e879fd1c9bdb6b1b0d9b7 (diff)
downloadlinux-5c27f4ee447b4ef1cd88d5313eeb838c56265571.tar.xz
f2fs: merge two uchar variable in struct node_info to reduce memory cost
This patch moves one member of struct nat_entry: _flag_ to struct node_info, so _version_ in struct node_info and _flag_ which are unsigned char type will merge to one 32-bit space in register/memory. So the size of nat_entry will be reduced from 28 bytes to 24 bytes (for 64-bit machine, reduce its size from 40 bytes to 32 bytes) and then slab memory using by f2fs will be reduced. changes from v2: o update description of memory usage gain for 64-bit machine suggested by Changman Lee. changes from v1: o introduce inline copy_node_info() to copy valid data from node info suggested by Jaegeuk Kim, it can avoid bug. Reviewed-by: Changman Lee <cm224.lee@samsung.com> Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs/node.h')
-rw-r--r--fs/f2fs/node.h33
1 files changed, 22 insertions, 11 deletions
diff --git a/fs/f2fs/node.h b/fs/f2fs/node.h
index 036b887176ff..fa6f95968b42 100644
--- a/fs/f2fs/node.h
+++ b/fs/f2fs/node.h
@@ -29,6 +29,14 @@
/* return value for read_node_page */
#define LOCKED_PAGE 1
+/* For flag in struct node_info */
+enum {
+ IS_CHECKPOINTED, /* is it checkpointed before? */
+ HAS_FSYNCED_INODE, /* is the inode fsynced before? */
+ HAS_LAST_FSYNC, /* has the latest node fsync mark? */
+ IS_DIRTY, /* this nat entry is dirty? */
+};
+
/*
* For node information
*/
@@ -37,18 +45,11 @@ struct node_info {
nid_t ino; /* inode number of the node's owner */
block_t blk_addr; /* block address of the node */
unsigned char version; /* version of the node */
-};
-
-enum {
- IS_CHECKPOINTED, /* is it checkpointed before? */
- HAS_FSYNCED_INODE, /* is the inode fsynced before? */
- HAS_LAST_FSYNC, /* has the latest node fsync mark? */
- IS_DIRTY, /* this nat entry is dirty? */
+ unsigned char flag; /* for node information bits */
};
struct nat_entry {
struct list_head list; /* for clean or dirty nat list */
- unsigned char flag; /* for node information bits */
struct node_info ni; /* in-memory node information */
};
@@ -63,20 +64,30 @@ struct nat_entry {
#define inc_node_version(version) (++version)
+static inline void copy_node_info(struct node_info *dst,
+ struct node_info *src)
+{
+ dst->nid = src->nid;
+ dst->ino = src->ino;
+ dst->blk_addr = src->blk_addr;
+ dst->version = src->version;
+ /* should not copy flag here */
+}
+
static inline void set_nat_flag(struct nat_entry *ne,
unsigned int type, bool set)
{
unsigned char mask = 0x01 << type;
if (set)
- ne->flag |= mask;
+ ne->ni.flag |= mask;
else
- ne->flag &= ~mask;
+ ne->ni.flag &= ~mask;
}
static inline bool get_nat_flag(struct nat_entry *ne, unsigned int type)
{
unsigned char mask = 0x01 << type;
- return ne->flag & mask;
+ return ne->ni.flag & mask;
}
static inline void nat_reset_flag(struct nat_entry *ne)