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

@@ -23,10 +23,11 @@ static inline void frozen_process(void)
}
/* Refrigerator is place where frozen processes are stored :-). */
void refrigerator(void)
bool __refrigerator(void)
{
/* Hmm, should we be allowed to suspend when there are realtime
processes around? */
bool was_frozen = false;
long save;
task_lock(current);
@@ -35,7 +36,7 @@ void refrigerator(void)
task_unlock(current);
} else {
task_unlock(current);
return;
return was_frozen;
}
save = current->state;
pr_debug("%s entered refrigerator\n", current->comm);
@@ -51,6 +52,7 @@ void refrigerator(void)
set_current_state(TASK_UNINTERRUPTIBLE);
if (!frozen(current))
break;
was_frozen = true;
schedule();
}
@@ -65,8 +67,10 @@ void refrigerator(void)
* synchronization which depends on ordered task state change.
*/
set_current_state(save);
return was_frozen;
}
EXPORT_SYMBOL(refrigerator);
EXPORT_SYMBOL(__refrigerator);
static void fake_signal_wake_up(struct task_struct *p)
{