Sorry for the long delay on this. I got distracted by the anon_vma and page migration stuff. On Sat, Apr 17, 2010 at 12:48:20AM +0200, Johannes Weiner wrote: > On Thu, Apr 15, 2010 at 06:21:35PM +0100, Mel Gorman wrote: > > From: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx> > > > > Now very lots function in vmscan have `priority' argument. It consume > > stack slightly. To move it on struct scan_control reduce stack. > > I don't like this much because it obfuscates value communication. > > Functions no longer have obvious arguments and return values, as it's all > passed hidden in that struct. > > Do you think it's worth it? I would much rather see that thing die than > expand on it... I don't feel strongly enough to fight about it and reducing stack usage here isn't the "fix" anyway. I'll drop this patch for now. That aside, the page reclaim algorithm maintains a lot of state and the "priority" is part of that state. While the struct means that functions might not have obvious arguments, passing the state around as arguments gets very unwieldly very quickly. I don't think killing scan_control would be as nice as you imagine although I do think it should be as small as possible. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>