procfs: reorder struct pid_dentry to save space on 64bit archs, and constify them
Change the order of fields of struct pid_entry (file fs/proc/base.c) in order
to avoid a hole on 64bit archs. (8 bytes saved per object)
Also change all pid_entry arrays to be const qualified, to make clear they
must not be modified.
Before (on x86_64) :
# size fs/proc/base.o
text data bss dec hex filename
15549 2192 0 17741 454d fs/proc/base.o
After :
# size fs/proc/base.o
text data bss dec hex filename
17229 176 0 17405 43fd fs/proc/base.o
Thats 336 bytes saved on kernel size on x86_64
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 17f7a7e..be94dde 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -91,8 +91,8 @@
#define PROC_NUMBUF 13
struct pid_entry {
- int len;
char *name;
+ int len;
mode_t mode;
const struct inode_operations *iop;
const struct file_operations *fop;
@@ -100,8 +100,8 @@
};
#define NOD(NAME, MODE, IOP, FOP, OP) { \
- .len = sizeof(NAME) - 1, \
.name = (NAME), \
+ .len = sizeof(NAME) - 1, \
.mode = MODE, \
.iop = IOP, \
.fop = FOP, \
@@ -1159,7 +1159,8 @@
/* Lookups */
-typedef struct dentry *instantiate_t(struct inode *, struct dentry *, struct task_struct *, void *);
+typedef struct dentry *instantiate_t(struct inode *, struct dentry *,
+ struct task_struct *, const void *);
/*
* Fill a directory entry.
@@ -1175,7 +1176,7 @@
*/
static int proc_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
char *name, int len,
- instantiate_t instantiate, struct task_struct *task, void *ptr)
+ instantiate_t instantiate, struct task_struct *task, const void *ptr)
{
struct dentry *child, *dir = filp->f_path.dentry;
struct inode *inode;
@@ -1310,9 +1311,9 @@
};
static struct dentry *proc_fd_instantiate(struct inode *dir,
- struct dentry *dentry, struct task_struct *task, void *ptr)
+ struct dentry *dentry, struct task_struct *task, const void *ptr)
{
- unsigned fd = *(unsigned *)ptr;
+ unsigned fd = *(const unsigned *)ptr;
struct file *file;
struct files_struct *files;
struct inode *inode;
@@ -1478,9 +1479,9 @@
};
static struct dentry *proc_pident_instantiate(struct inode *dir,
- struct dentry *dentry, struct task_struct *task, void *ptr)
+ struct dentry *dentry, struct task_struct *task, const void *ptr)
{
- struct pid_entry *p = ptr;
+ const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-EINVAL);
@@ -1509,13 +1510,13 @@
static struct dentry *proc_pident_lookup(struct inode *dir,
struct dentry *dentry,
- struct pid_entry *ents,
+ const struct pid_entry *ents,
unsigned int nents)
{
struct inode *inode;
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
- struct pid_entry *p, *last;
+ const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
inode = NULL;
@@ -1544,8 +1545,8 @@
return error;
}
-static int proc_pident_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
- struct task_struct *task, struct pid_entry *p)
+static int proc_pident_fill_cache(struct file *filp, void *dirent,
+ filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
{
return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
proc_pident_instantiate, task, p);
@@ -1553,14 +1554,14 @@
static int proc_pident_readdir(struct file *filp,
void *dirent, filldir_t filldir,
- struct pid_entry *ents, unsigned int nents)
+ const struct pid_entry *ents, unsigned int nents)
{
int i;
int pid;
struct dentry *dentry = filp->f_path.dentry;
struct inode *inode = dentry->d_inode;
struct task_struct *task = get_proc_task(inode);
- struct pid_entry *p, *last;
+ const struct pid_entry *p, *last;
ino_t ino;
int ret;
@@ -1675,7 +1676,7 @@
.write = proc_pid_attr_write,
};
-static struct pid_entry attr_dir_stuff[] = {
+static const struct pid_entry attr_dir_stuff[] = {
REG("current", S_IRUGO|S_IWUGO, pid_attr),
REG("prev", S_IRUGO, pid_attr),
REG("exec", S_IRUGO|S_IWUGO, pid_attr),
@@ -1741,7 +1742,7 @@
* that properly belong to the /proc filesystem, as they describe
* describe something that is process related.
*/
-static struct pid_entry proc_base_stuff[] = {
+static const struct pid_entry proc_base_stuff[] = {
NOD("self", S_IFLNK|S_IRWXUGO,
&proc_self_inode_operations, NULL, {}),
};
@@ -1770,9 +1771,9 @@
};
static struct dentry *proc_base_instantiate(struct inode *dir,
- struct dentry *dentry, struct task_struct *task, void *ptr)
+ struct dentry *dentry, struct task_struct *task, const void *ptr)
{
- struct pid_entry *p = ptr;
+ const struct pid_entry *p = ptr;
struct inode *inode;
struct proc_inode *ei;
struct dentry *error = ERR_PTR(-EINVAL);
@@ -1820,7 +1821,7 @@
{
struct dentry *error;
struct task_struct *task = get_proc_task(dir);
- struct pid_entry *p, *last;
+ const struct pid_entry *p, *last;
error = ERR_PTR(-ENOENT);
@@ -1846,8 +1847,8 @@
return error;
}
-static int proc_base_fill_cache(struct file *filp, void *dirent, filldir_t filldir,
- struct task_struct *task, struct pid_entry *p)
+static int proc_base_fill_cache(struct file *filp, void *dirent,
+ filldir_t filldir, struct task_struct *task, const struct pid_entry *p)
{
return proc_fill_cache(filp, dirent, filldir, p->name, p->len,
proc_base_instantiate, task, p);
@@ -1884,7 +1885,7 @@
static const struct file_operations proc_task_operations;
static const struct inode_operations proc_task_inode_operations;
-static struct pid_entry tgid_base_stuff[] = {
+static const struct pid_entry tgid_base_stuff[] = {
DIR("task", S_IRUGO|S_IXUGO, task),
DIR("fd", S_IRUSR|S_IXUSR, fd),
INF("environ", S_IRUSR, pid_environ),
@@ -2027,7 +2028,7 @@
static struct dentry *proc_pid_instantiate(struct inode *dir,
struct dentry * dentry,
- struct task_struct *task, void *ptr)
+ struct task_struct *task, const void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;
@@ -2142,7 +2143,7 @@
goto out_no_task;
for (; nr < ARRAY_SIZE(proc_base_stuff); filp->f_pos++, nr++) {
- struct pid_entry *p = &proc_base_stuff[nr];
+ const struct pid_entry *p = &proc_base_stuff[nr];
if (proc_base_fill_cache(filp, dirent, filldir, reaper, p) < 0)
goto out;
}
@@ -2168,7 +2169,7 @@
/*
* Tasks
*/
-static struct pid_entry tid_base_stuff[] = {
+static const struct pid_entry tid_base_stuff[] = {
DIR("fd", S_IRUSR|S_IXUSR, fd),
INF("environ", S_IRUSR, pid_environ),
INF("auxv", S_IRUSR, pid_auxv),
@@ -2238,7 +2239,7 @@
};
static struct dentry *proc_task_instantiate(struct inode *dir,
- struct dentry *dentry, struct task_struct *task, void *ptr)
+ struct dentry *dentry, struct task_struct *task, const void *ptr)
{
struct dentry *error = ERR_PTR(-ENOENT);
struct inode *inode;