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[PATCH] inode_diet: Replace inode.u.generic_ip with inode.i_private

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The following patches reduce the size of the VFS inode structure by 28 bytes
on a UP x86.  (It would be more on an x86_64 system).  This is a 10% reduction
in the inode size on a UP kernel that is configured in a production mode
(i.e., with no spinlock or other debugging functions enabled; if you want to
save memory taken up by in-core inodes, the first thing you should do is
disable the debugging options; they are responsible for a huge amount of bloat
in the VFS inode structure).

This patch:

The filesystem or device-specific pointer in the inode is inside a union,
which is pretty pointless given that all 30+ users of this field have been
using the void pointer.  Get rid of the union and rename it to i_private, with
a comment to explain who is allowed to use the void pointer.  This is just a
cleanup, but it allows us to reuse the union 'u' for something something where
the union will actually be used.

[judith@osdl.org: powerpc build fix]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Judith Lebzelter <judith@osdl.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Theodore Ts'o
2006-09-27 01:50:46 -07:00
committed by Linus Torvalds
parent 6a1d9805ec
commit 8e18e2941c
36 changed files with 88 additions and 90 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/infiniband/hw/ipath/ipath_fs.c
View File

@ -64,7 +64,7 @@ static int ipathfs_mknod(struct inode *dir, struct dentry *dentry,
inode->i_blksize = PAGE_CACHE_SIZE;
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
inode->u.generic_ip = data;
inode->i_private = data;
if ((mode & S_IFMT) == S_IFDIR) {
inode->i_op = &simple_dir_inode_operations;
inode->i_nlink++;
@ -119,7 +119,7 @@ static ssize_t atomic_counters_read(struct file *file, char __user *buf,
u16 i;
struct ipath_devdata *dd;
dd = file->f_dentry->d_inode->u.generic_ip;
dd = file->f_dentry->d_inode->i_private;
for (i = 0; i < NUM_COUNTERS; i++)
counters[i] = ipath_snap_cntr(dd, i);
@ -139,7 +139,7 @@ static ssize_t atomic_node_info_read(struct file *file, char __user *buf,
struct ipath_devdata *dd;
u64 guid;
dd = file->f_dentry->d_inode->u.generic_ip;
dd = file->f_dentry->d_inode->i_private;
guid = be64_to_cpu(dd->ipath_guid);
@ -178,7 +178,7 @@ static ssize_t atomic_port_info_read(struct file *file, char __user *buf,
u32 tmp, tmp2;
struct ipath_devdata *dd;
dd = file->f_dentry->d_inode->u.generic_ip;
dd = file->f_dentry->d_inode->i_private;
/* so we only initialize non-zero fields. */
memset(portinfo, 0, sizeof portinfo);
@ -325,7 +325,7 @@ static ssize_t flash_read(struct file *file, char __user *buf,
goto bail;
}
dd = file->f_dentry->d_inode->u.generic_ip;
dd = file->f_dentry->d_inode->i_private;
if (ipath_eeprom_read(dd, pos, tmp, count)) {
ipath_dev_err(dd, "failed to read from flash\n");
ret = -ENXIO;
@ -381,7 +381,7 @@ static ssize_t flash_write(struct file *file, const char __user *buf,
goto bail_tmp;
}
dd = file->f_dentry->d_inode->u.generic_ip;
dd = file->f_dentry->d_inode->i_private;
if (ipath_eeprom_write(dd, pos, tmp, count)) {
ret = -ENXIO;
ipath_dev_err(dd, "failed to write to flash\n");