Ar Mer, 2006-08-30 am 08:21 -0400, ysgrifennodd Hall, Ken (GTI): > We've been going around trying to figure out: 1) why we suddenly > should have run out of virtual memory (if we did, because we never > even got close to that before), and 2) why it was reported in this > way. Does anyone know if there's anything in the swap space > management mechanism that would cause Linux to fail malloc if a single > swap partition fills up? Is there some kind of process affinity for > paging to swap spaces?
#1 no idea - maybe you hit a worst case or a memory leak in it ? Java and other garbage collectors are also a common source of large brief spikes in memory usage. #2 Linux uses the swap according to the priority of the swap files and swap partitions. When one fills it will move onto the next. Memory allocations are failed according to the overcommit settings. The default behaviour is "fail allocations that will obviously fail". This allows overcommit of resources (so you can get process kills due to out of memory) but tries to avoid obvious cases. A seperate mode is available which assumes all allocation requests should be allowed until the box goes totally out of memory. This is only for specialist scientific applications The third mode prevents overcommit and will fail allocations when it is theoretically possible for an overcommit situation to occur, this is used for high reliability environments where having to deploy extra swap "just in case" is preferable to, say, having your air traffic control system self destruct. Alan ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
