Re: [PATCH 07/10] mm: base LRU balancing on an explicit cost model

From: Johannes Weiner <hannes@cmpxchg.org>
To: Michal Hocko <mhocko@kernel.org>
Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org,
	Andrew Morton <akpm@linux-foundation.org>,
	Rik van Riel <riel@redhat.com>, Mel Gorman <mgorman@suse.de>,
	Andrea Arcangeli <aarcange@redhat.com>,
	Andi Kleen <andi@firstfloor.org>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	kernel-team@fb.com
Subject: Re: [PATCH 07/10] mm: base LRU balancing on an explicit cost model
Date: Thu, 9 Jun 2016 09:33:31 -0400	[thread overview]
Message-ID: <20160609133331.GB11719@cmpxchg.org> (raw)
In-Reply-To: <20160609121802.GD24777@dhcp22.suse.cz>

On Thu, Jun 09, 2016 at 02:18:02PM +0200, Michal Hocko wrote:
> On Wed 08-06-16 12:16:05, Johannes Weiner wrote:
> > On Wed, Jun 08, 2016 at 02:51:37PM +0200, Michal Hocko wrote:
> > > On Mon 06-06-16 15:48:33, Johannes Weiner wrote:
> > > > Rename struct zone_reclaim_stat to struct lru_cost, and move from two
> > > > separate value ratios for the LRU lists to a relative LRU cost metric
> > > > with a shared denominator.
> > > 
> > > I just do not like the too generic `number'. I guess cost or price would
> > > fit better and look better in the code as well. Up you though...
> > 
> > Yeah, I picked it as a pair, numerator and denominator. But as Minchan
> > points out, denom is superfluous in the final version of the patch, so
> > I'm going to remove it and give the numerators better names.
> > 
> > anon_cost and file_cost?
> 
> Yes that is much more descriptive and easier to grep for. I didn't
> propose that because I thought you would want to preserve the array
> definition for an easier code to update them.

It'll be slightly more verbose, but that's probably a good thing.
Especially for readability in get_scan_count().