[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20110818165428.4f01a1b9.akpm@linux-foundation.org>
Date: Thu, 18 Aug 2011 16:54:28 -0700
From: Andrew Morton <akpm@...ux-foundation.org>
To: Mel Gorman <mgorman@...e.de>
Cc: Linux-MM <linux-mm@...ck.org>, LKML <linux-kernel@...r.kernel.org>,
XFS <xfs@....sgi.com>, Dave Chinner <david@...morbit.com>,
Christoph Hellwig <hch@...radead.org>,
Johannes Weiner <jweiner@...hat.com>,
Wu Fengguang <fengguang.wu@...el.com>, Jan Kara <jack@...e.cz>,
Rik van Riel <riel@...hat.com>,
Minchan Kim <minchan.kim@...il.com>
Subject: Re: [PATCH 6/7] mm: vmscan: Throttle reclaim if encountering too
many dirty pages under writeback
On Wed, 10 Aug 2011 11:47:19 +0100
Mel Gorman <mgorman@...e.de> wrote:
> The percentage that must be in writeback depends on the priority. At
> default priority, all of them must be dirty. At DEF_PRIORITY-1, 50%
> of them must be, DEF_PRIORITY-2, 25% etc. i.e. as pressure increases
> the greater the likelihood the process will get throttled to allow
> the flusher threads to make some progress.
It'd be nice if the code comment were to capture this piece of implicit
arithmetic. After all, it's a magic number and magic numbers should
stick out like sore thumbs.
And.. how do we know that the chosen magic numbers were optimal?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists