Date: Thu, 27 Oct 2016 17:00:39 +0200
From: Peter Zijlstra <peterz@infradead.org>
To: David Herrmann <dh.herrmann@gmail.com>
Cc: linux-kernel@vger.kernel.org, Andy Lutomirski <luto@amacapital.net>,
        Jiri Kosina <jikos@kernel.org>, Greg KH <greg@kroah.com>,
        Hannes Reinecke <hare@suse.com>, Steven Rostedt <rostedt@goodmis.org>,
        Arnd Bergmann <arnd@arndb.de>, Tom Gundersen <teg@jklm.no>,
        Josh Triplett <josh@joshtriplett.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [RFC v1 05/14] bus1: util - pool utility library
Message-ID: <20161027150039.GK3157@twins.programming.kicks-ass.net>
References: <20161026191810.12275-1-dh.herrmann@gmail.com>
 <20161026191810.12275-6-dh.herrmann@gmail.com>
 <20161027125907.GF3175@twins.programming.kicks-ass.net>
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On Thu, Oct 27, 2016 at 02:59:07PM +0200, Peter Zijlstra wrote:
> On Wed, Oct 26, 2016 at 09:18:01PM +0200, David Herrmann wrote:
> > +/* insert slice into the free tree */
> > +static void bus1_pool_slice_link_free(struct bus1_pool_slice *slice,
> > +				      struct bus1_pool *pool)
> > +{
> > +	struct rb_node **n, *prev = NULL;
> > +	struct bus1_pool_slice *ps;
> > +
> > +	n = &pool->slices_free.rb_node;
> > +	while (*n) {
> > +		prev = *n;
> > +		ps = container_of(prev, struct bus1_pool_slice, rb);
> > +		if (slice->size < ps->size)
> > +			n = &prev->rb_left;
> > +		else
> > +			n = &prev->rb_right;
> > +	}
> > +
> > +	rb_link_node(&slice->rb, prev, n);
> > +	rb_insert_color(&slice->rb, &pool->slices_free);
> > +}
> 
> If you only sort free slices by size, how do you merge contiguous free
> slices?

Ah, I see, you also keep an ordered list of slices and use that one
function up from here.