freezer: unexport refrigerator() and update try_to_freeze() slightly

There is no reason to export two functions for entering the
refrigerator.  Calling refrigerator() instead of try_to_freeze()
doesn't save anything noticeable or removes any race condition.

* Rename refrigerator() to __refrigerator() and make it return bool
  indicating whether it scheduled out for freezing.

* Update try_to_freeze() to return bool and relay the return value of
  __refrigerator() if freezing().

* Convert all refrigerator() users to try_to_freeze().

* Update documentation accordingly.

* While at it, add might_sleep() to try_to_freeze().

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Samuel Ortiz <samuel@sortiz.org>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp>
Cc: Christoph Hellwig <hch@infradead.org>
This commit is contained in:
Tejun Heo
2011-11-21 12:32:22 -08:00
parent 3a7cbd50f7
commit a0acae0e88
15 changed files with 37 additions and 39 deletions

View File

@ -47,18 +47,17 @@ static inline bool should_send_signal(struct task_struct *p)
/* Takes and releases task alloc lock using task_lock() */
extern int thaw_process(struct task_struct *p);
extern void refrigerator(void);
extern bool __refrigerator(void);
extern int freeze_processes(void);
extern int freeze_kernel_threads(void);
extern void thaw_processes(void);
static inline int try_to_freeze(void)
static inline bool try_to_freeze(void)
{
if (freezing(current)) {
refrigerator();
return 1;
} else
return 0;
might_sleep();
if (likely(!freezing(current)))
return false;
return __refrigerator();
}
extern bool freeze_task(struct task_struct *p, bool sig_only);
@ -181,12 +180,12 @@ static inline void set_freeze_flag(struct task_struct *p) {}
static inline void clear_freeze_flag(struct task_struct *p) {}
static inline int thaw_process(struct task_struct *p) { return 1; }
static inline void refrigerator(void) {}
static inline bool __refrigerator(void) { return false; }
static inline int freeze_processes(void) { return -ENOSYS; }
static inline int freeze_kernel_threads(void) { return -ENOSYS; }
static inline void thaw_processes(void) {}
static inline int try_to_freeze(void) { return 0; }
static inline bool try_to_freeze(void) { return false; }
static inline void freezer_do_not_count(void) {}
static inline void freezer_count(void) {}