Re: [PATCH] Convert refrigerator() to try_to_freeze()

[Nigel Cunningham <ncunningham@cyclades.com>]

Hi.

On Tue, 2005-07-19 at 23:54, Pavel Machek wrote:
> Hi!
> 
> > This patch removes the few remaining direct invocations of the
> > refrigerator in 2.6.13-rc3. In drivers/media/video/msp3400.c, it also
> > shifts the call to after the remove_wait_queue; this seems to be the
> > more appropriate place.
> 
> 
> > diff -ruNp 230-refrigerator-to-try_to_freeze.patch-old/fs/jbd/journal.c 230-refrigerator-to-try_to_freeze.patch-new/fs/jbd/journal.c
> > --- 230-refrigerator-to-try_to_freeze.patch-old/fs/jbd/journal.c	2005-07-18 06:36:59.000000000 +1000
> > +++ 230-refrigerator-to-try_to_freeze.patch-new/fs/jbd/journal.c	2005-07-18 13:54:47.000000000 +1000
> > @@ -175,7 +175,7 @@ loop:
> >  		 */
> >  		jbd_debug(1, "Now suspending kjournald\n");
> >  		spin_unlock(&journal->j_state_lock);
> > -		refrigerator();
> > +		try_to_freeze();
> >  		spin_lock(&journal->j_state_lock);
> >  	} else {
> >  		/*
> 
> They probably tested it before, why test again?
> 
> > diff -ruNp 230-refrigerator-to-try_to_freeze.patch-old/fs/jfs/jfs_logmgr.c 230-refrigerator-to-try_to_freeze.patch-new/fs/jfs/jfs_logmgr.c
> > --- 230-refrigerator-to-try_to_freeze.patch-old/fs/jfs/jfs_logmgr.c	2005-07-18 06:36:59.000000000 +1000
> > +++ 230-refrigerator-to-try_to_freeze.patch-new/fs/jfs/jfs_logmgr.c	2005-07-18 13:54:47.000000000 +1000
> > @@ -2361,7 +2361,7 @@ int jfsIOWait(void *arg)
> >  		}
> >  		if (freezing(current)) {
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >  			spin_unlock_irq(&log_redrive_lock);
> > -			refrigerator();
> > +			try_to_freeze();
> >  		} else {
> >  			add_wait_queue(&jfs_IO_thread_wait, &wq);
> >  			set_current_state(TASK_INTERRUPTIBLE);
> 
> See? You are needlessly testing condition twice.

True. I was just concerned that things are messy and inconsistent as
they stand (sometimes we use try_to_freeze and implicitly call
refrigerator(), sometimes we call freezing() and refrigerator). *shrug*

Regards,

Nigel
-- 
Evolution.
Enumerate the requirements.
Consider the interdependencies.
Calculate the probabilities.