On 06/22/2011 07:37 PM, Nai Xia wrote:
On 2MB pages, I'd like to remind you and Rik that ksmd currently splits huge pages before their sub pages gets really merged to stable tree.
Your proposal appears to add a condition that causes ksmd to skip doing that, which can cause the system to start using swap instead of sharing memory.
So when there are many 2MB pages each having a 4kB subpage changed for all time, this is already a concern for ksmd to judge if it's worthwhile to split 2MB page and get its sub-pages merged. I think the policy for ksmd in a system should be "If you cannot do sth good, at least do nothing evil". So I really don't think we can satisfy _all_ people. Get a general method and give users one or two knobs to tune it when they are the corner cases. How do you think of my proposal ?
I think your proposal makes sense for 4kB pages, but the ksmd policy for 2MB pages probably needs to be much more aggressive. -- All rights reversed -- 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>