On Wed, 12 Oct 2011 17:01:21 -0700 (PDT) David Rientjes <rientjes@xxxxxxxxxx> wrote: > On Wed, 12 Oct 2011, Satoru Moriya wrote: > > I understand what you concern. But in some area such as banking, > > stock exchange, train/power/plant control sysemts etc this kind > > of tunable is welcomed because they can tune their systems at > > their own risk. > > > > You haven't tried the patch that increases the priority of kswapd when > such a latency sensitive thread triggers background reclaim? I don't read full story but....how about adding a new syscall like == sys_mem_shrink(int nid, int nr_scan_pages, int flags) This system call scans LRU of specified nodes and free pages on LRU. This scan nr_scan_pages in LRU and returns the number of successfully freed pages. == Then, running this progam in SCHED_IDLE, a user can make free pages while the system is idle. If running in the highest priority, a user can keep free pages as he want. If a user run this under a memcg, user can free pages in a memcg. Maybe many guys don't want to export memory-shrink facility to userland ;) This is just an idea. Thanks, -Kame -- 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>