On Wed, 10 Aug 2011 11:47:13 +0100 Mel Gorman <mgorman@xxxxxxx> wrote: > The new problem is that > reclaim has very little control over how long before a page in a > particular zone or container is cleaned which is discussed later. Confused - where was this discussed? Please tell us more about this problem and how it was addressed. Another (and somewhat interrelated) potential problem I see with this work is that it throws a big dependency onto kswapd. If kswapd gets stuck somewhere for extended periods, there's nothing there to perform direct writeback. This has happened in the past in weird situations such as kswpad getting blocked on ext3 journal commits which are themselves stuck for ages behind lots of writeout which itself is stuck behind lots of reads. That's an advantage of direct reclaim: more threads available. How forcefully has this stuff been tested with multiple disks per kswapd? Where one disk is overloaded-ext3-on-usb-stick? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>