Commit 81132a39 authored by Gou Hao's avatar Gou Hao Committed by Al Viro
Browse files

fs: remove fget_many and fput_many interface 



These two interface were added in 091141a4 commit,
but now there is no place to call them.

The only user of fput/fget_many() was removed in commit
62906e89 ("io_uring: remove file batch-get optimisation").

A user of get_file_rcu_many() were removed in commit
f0735310 ("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: default avatarGou Hao <gouhao@uniontech.com>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 4329490a

fs/file.c

+13 −20
Original line number Diff line number Diff line
@@ -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)

{

	return __fget_files(current->files, fd, mask, refs);

}



struct file *fget_many(unsigned int fd, unsigned int refs)

static inline struct file *__fget(unsigned int fd, fmode_t mask)

{

	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;

fs/file_table.c

+2 −7
Original line number Diff line number Diff line
@@ -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

include/linux/file.h

+0 −2
Original line number Diff line number Diff line
@@ -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);

include/linux/fs.h

+1 −3
Original line number Diff line number Diff line
@@ -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)