On Mon, 11 Apr 2011, Dave Hansen wrote: > > This patch raise zone_reclaim_mode threshold to 30. 30 don't have > > specific meaning. but 20 mean one-hop QPI/Hypertransport and such > > relatively cheap 2-4 socket machine are often used for tradiotional > > server as above. The intention is, their machine don't use > > zone_reclaim_mode. > > I know specifically of pieces of x86 hardware that set the information > in the BIOS to '21' *specifically* so they'll get the zone_reclaim_mode > behavior which that implies. > That doesn't seem like an argument against this patch, it's an improper configuration unless the remote memory access has a latency of 2.1x that of a local access between those two nodes. If that's the case, then it's accurately following the ACPI spec and the VM has made its policy decision to enable zone_reclaim_mode as a result. I'm surprised that they'd play with their BIOS to enable this by default, those, when it's an easily tunable sysctl. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>