On 29 Sep 11 13:19, Andi Kleen wrote: > Larry Bassel <lbassel@xxxxxxxxxxxxxx> writes: > > > > It was suggested to me that a new zone type which would be similar > > to the "movable zone" but is only allowed to contain pages > > that can be discarded (such as text) could solve this problem, > > This may not actually be a win because if the text pages are needed > afterwards the act of rereading them from disk would likely take longer > than the copying. Yes, I'm aware of this (they'd actually be coming from flash which is even slower, right?). > > The so you many not get latency before, but after. > > Essentially robbing Peter to pay Paul. Yes, the goal is to create this large contiguous memory quickly, even if performance is worse later on for a while. > > If the goal is to just spread the latency over a longer time > I'm sure there are better ways to do that than to add a new zone. I myself am not an advocate of creating this new zone (because I think there may not be a lot of benefit to it for the amount of work involved), but I want to solicit people's opinions about it and collect suggestions (such as Dan's) about alternate approaches that may be better/closer to already implemented (I'd likely have to port them to ARM as they probably were developed for x86, but I don't think that's a problem) that will handle our use case. I wonder if another reasonable approach might be a combination of memory compaction in the background when the machine is otherwise idle, combined with occasional killing of processes that haven't been used for a long time (this is going to be run on an android user environment, android likes to leave lots of unused processes running in the background). > > -Andi Larry -- Sent by an employee of the Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum. -- 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>