Re: [OMPI users] Avoiding the memory registration costs by having memory always registered, is it possible with Linux ?

2016-06-27 Thread Brice Goglin
mlock() and mlockall() only guarantee that pages won't be swapped out to the disk. However, they don't prevent virtual pages from moving to other physical pages (for instance during migration between NUMA nodes), which breaks memory registration. At least this was true a couple years ago, I didn't

Re: [OMPI users] Avoiding the memory registration costs by having memory always registered, is it possible with Linux ?

2016-06-27 Thread Audet, Martin
Thanks Jeff and Alex for your answers and comments. mlockall(), especially with the MCL_FUTURE argument is indeed interesting. Thanks Jeff for your clarification of what memory registration really means (e.g. locking and telling the network stack the virtual to physical mapping). Also