From mboxrd@z Thu Jan  1 00:00:00 1970
From: Dave Chinner <david@fromorbit.com>
Subject: Re: [PATCH v2 08/28] list: add a new LRU list type
Date: Fri, 5 Apr 2013 12:20:48 +1100
Message-ID: <20130405012048.GH12011@dastard>
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Cc: Glauber Costa <glommer@parallels.com>, linux-mm@kvack.org,
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	Michal Hocko <mhocko@suse.cz>,
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	Andrew Morton <akpm@linux-foundation.org>, hughd@google.com,
	yinghan@google.com, Dave Chinner <dchinner@redhat.com>
To: Greg Thelen <gthelen@google.com>
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On Thu, Apr 04, 2013 at 02:53:49PM -0700, Greg Thelen wrote:
> On Fri, Mar 29 2013, Glauber Costa wrote:
> > From: Dave Chinner <dchinner@redhat.com>
> > +long
> > +list_lru_walk(
> > +	struct list_lru *lru,
> > +	list_lru_walk_cb isolate,
> > +	void		*cb_arg,
> > +	long		nr_to_walk)
> > +{
> > +	struct list_head *item, *n;
> > +	long removed = 0;
> > +restart:
> > +	spin_lock(&lru->lock);
> > +	list_for_each_safe(item, n, &lru->list) {
> > +		int ret;
> > +
> > +		if (nr_to_walk-- < 0)
> > +			break;
> > +
> > +		ret = isolate(item, &lru->lock, cb_arg);
> > +		switch (ret) {
> > +		case 0:	/* item removed from list */
> > +			lru->nr_items--;
> > +			removed++;
> > +			break;
> > +		case 1: /* item referenced, give another pass */
> > +			list_move_tail(item, &lru->list);
> > +			break;
> > +		case 2: /* item cannot be locked, skip */
> > +			break;
> > +		case 3: /* item not freeable, lock dropped */
> > +			goto restart;
> 
> These four magic return values might benefit from an enum (or #define)
> for clarity.

Obviously, and it was stated that this needed to be done by miself
when I last posted the patch set many months ago. I've been rather
busy since then, and so haven't had time to do anything with it.

> Maybe the names would be LRU_OK, LRU_REMOVED, LRU_ROTATE, LRU_RETRY.

Something like that...

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com