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fs: remove fget_many and fput_many interface 

These two interface were added in 091141a42 commit,
but now there is no place to call them.

The only user of fput/fget_many() was removed in commit
62906e89e6 ("io_uring: remove file batch-get optimisation").

A user of get_file_rcu_many() were removed in commit
f073531070 ("init: add an init_dup helper").

And replace atomic_long_sub/add to atomic_long_dec/inc
can improve performance.

Here are the test results of unixbench:

Cmd: ./Run -c 64 context1

Without patch:
System Benchmarks Partial Index              BASELINE       RESULT    INDEX
Pipe-based Context Switching                   4000.0    2798407.0   6996.0
                                                                   ========
System Benchmarks Index Score (Partial Only)                         6996.0

With patch:
System Benchmarks Partial Index              BASELINE       RESULT    INDEX
Pipe-based Context Switching                   4000.0    3486268.8   8715.7
                                                                   ========
System Benchmarks Index Score (Partial Only)                         8715.7

Signed-off-by: Gou Hao <gouhao@uniontech.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Gou Hao 2021-11-02 10:46:48 +08:00 committed by Al Viro
parent 4329490a78
commit 81132a39c1
4 changed files with 16 additions and 32 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
fs/file.c
View File

@ -871,7 +871,7 @@ void do_close_on_exec(struct files_struct *files)
}
static inline struct file *__fget_files_rcu(struct files_struct *files,
unsigned int fd, fmode_t mask, unsigned int refs)
unsigned int fd, fmode_t mask)
{
for (;;) {
struct file *file;
@ -897,10 +897,9 @@ static inline struct file *__fget_files_rcu(struct files_struct *files,
* Such a race can take two forms:
*
* (a) the file ref already went down to zero,
* and get_file_rcu_many() fails. Just try
* again:
* and get_file_rcu() fails. Just try again:
*/
if (unlikely(!get_file_rcu_many(file, refs)))
if (unlikely(!get_file_rcu(file)))
continue;
/*
@ -909,11 +908,11 @@ static inline struct file *__fget_files_rcu(struct files_struct *files,
* pointer having changed, because it always goes
* hand-in-hand with 'fdt'.
*
* If so, we need to put our refs and try again.
* If so, we need to put our ref and try again.
*/
if (unlikely(rcu_dereference_raw(files->fdt) != fdt) ||
unlikely(rcu_dereference_raw(*fdentry) != file)) {
fput_many(file, refs);
fput(file);
continue;
}
@ -926,37 +925,31 @@ static inline struct file *__fget_files_rcu(struct files_struct *files,
}
static struct file *__fget_files(struct files_struct *files, unsigned int fd,
fmode_t mask, unsigned int refs)
fmode_t mask)
{
struct file *file;
rcu_read_lock();
file = __fget_files_rcu(files, fd, mask, refs);
file = __fget_files_rcu(files, fd, mask);
rcu_read_unlock();
return file;
}
static inline struct file *__fget(unsigned int fd, fmode_t mask,
unsigned int refs)
static inline struct file *__fget(unsigned int fd, fmode_t mask)
{
return __fget_files(current->files, fd, mask, refs);
}
struct file *fget_many(unsigned int fd, unsigned int refs)
{
return __fget(fd, FMODE_PATH, refs);
return __fget_files(current->files, fd, mask);
}
struct file *fget(unsigned int fd)
{
return __fget(fd, FMODE_PATH, 1);
return __fget(fd, FMODE_PATH);
}
EXPORT_SYMBOL(fget);
struct file *fget_raw(unsigned int fd)
{
return __fget(fd, 0, 1);
return __fget(fd, 0);
}
EXPORT_SYMBOL(fget_raw);
@ -966,7 +959,7 @@ struct file *fget_task(struct task_struct *task, unsigned int fd)
task_lock(task);
if (task->files)
file = __fget_files(task->files, fd, 0, 1);
file = __fget_files(task->files, fd, 0);
task_unlock(task);
return file;
@ -1035,7 +1028,7 @@ static unsigned long __fget_light(unsigned int fd, fmode_t mask)
return 0;
return (unsigned long)file;
} else {
file = __fget(fd, mask, 1);
file = __fget(fd, mask);
if (!file)
return 0;
return FDPUT_FPUT | (unsigned long)file;

9
fs/file_table.c
View File

@ -368,9 +368,9 @@ EXPORT_SYMBOL_GPL(flush_delayed_fput);
static DECLARE_DELAYED_WORK(delayed_fput_work, delayed_fput);
void fput_many(struct file *file, unsigned int refs)
void fput(struct file *file)
{
if (atomic_long_sub_and_test(refs, &file->f_count)) {
if (atomic_long_dec_and_test(&file->f_count)) {
struct task_struct *task = current;
if (likely(!in_interrupt() && !(task->flags & PF_KTHREAD))) {
@ -389,11 +389,6 @@ void fput_many(struct file *file, unsigned int refs)
}
}
void fput(struct file *file)
{
fput_many(file, 1);
}
/*
* synchronous analog of fput(); for kernel threads that might be needed
* in some umount() (and thus can't use flush_delayed_fput() without

2
include/linux/file.h
View File

@ -14,7 +14,6 @@
struct file;
extern void fput(struct file *);
extern void fput_many(struct file *, unsigned int);
struct file_operations;
struct task_struct;
@ -47,7 +46,6 @@ static inline void fdput(struct fd fd)
}
extern struct file *fget(unsigned int fd);
extern struct file *fget_many(unsigned int fd, unsigned int refs);
extern struct file *fget_raw(unsigned int fd);
extern struct file *fget_task(struct task_struct *task, unsigned int fd);
extern unsigned long __fdget(unsigned int fd);

4
include/linux/fs.h
View File

@ -981,9 +981,7 @@ static inline struct file *get_file(struct file *f)
atomic_long_inc(&f->f_count);
return f;
}
#define get_file_rcu_many(x, cnt) \
atomic_long_add_unless(&(x)->f_count, (cnt), 0)
#define get_file_rcu(x) get_file_rcu_many((x), 1)
#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
#define file_count(x) atomic_long_read(&(x)->f_count)
#define MAX_NON_LFS ((1UL<<31) - 1)