* [PATCH] procfs : reorder struct pid_dentry to save space on 64bit archs, and constify them
[not found] <20070308101947.f77ab27f.akpm@linux-foundation.org>
@ 2007-03-08 19:40 ` Eric Dumazet
0 siblings, 0 replies; only message in thread
From: Eric Dumazet @ 2007-03-08 19:40 UTC (permalink / raw)
To: Andrew Morton; +Cc: linux-kernel
[-- Attachment #1: Type: text/plain, Size: 763 bytes --]
This patches changes 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)
It also changes 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>
fs/proc/base.c | 53 +++++++++++++++++++++++------------------------
1 file changed, 27 insertions(+), 26 deletions(-)
[-- Attachment #2: pid_entry.patch --]
[-- Type: text/plain, Size: 6918 bytes --]
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 01f7769..d71135b 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -90,8 +90,8 @@ #include "internal.h"
#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;
@@ -99,8 +99,8 @@ struct pid_entry {
};
#define NOD(NAME, MODE, IOP, FOP, OP) { \
- .len = sizeof(NAME) - 1, \
.name = (NAME), \
+ .len = sizeof(NAME) - 1, \
.mode = MODE, \
.iop = IOP, \
.fop = FOP, \
@@ -1121,7 +1121,8 @@ static struct dentry_operations pid_dent
/* 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.
@@ -1137,7 +1138,7 @@ typedef struct dentry *instantiate_t(str
*/
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;
@@ -1272,9 +1273,9 @@ static struct dentry_operations tid_fd_d
};
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;
@@ -1422,9 +1423,9 @@ static const struct inode_operations pro
};
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);
@@ -1453,13 +1454,13 @@ out:
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;
@@ -1488,8 +1489,8 @@ out_no_task:
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);
@@ -1497,14 +1498,14 @@ static int proc_pident_fill_cache(struct
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;
@@ -1628,7 +1629,7 @@ static const struct file_operations proc
.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),
@@ -1694,7 +1695,7 @@ static const struct inode_operations pro
* 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, {}),
};
@@ -1723,9 +1724,9 @@ static struct dentry_operations proc_bas
};
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);
@@ -1773,7 +1774,7 @@ static struct dentry *proc_base_lookup(s
{
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);
@@ -1799,8 +1800,8 @@ out_no_task:
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);
@@ -1837,7 +1838,7 @@ #endif
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),
@@ -1979,7 +1980,7 @@ out:
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;
@@ -2094,7 +2095,7 @@ int proc_pid_readdir(struct file * filp,
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;
}
@@ -2120,7 +2121,7 @@ out_no_task:
/*
* 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),
@@ -2189,7 +2190,7 @@ static const struct inode_operations pro
};
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;
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