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 check recently, but I would be surprised if that semantics changed.
Brice Le 27/06/2016 21:17, Audet, Martin a écrit : > 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 concerning the ummunotify kernel module, I would like to point > out that while the link sent to github bug report suggests it is > problematic, the top level Open MPI README file still recommends it. > Should the README file need to be updated ? > > Regards, > > Martin Audet > > > > _______________________________________________ > users mailing list > us...@open-mpi.org > Subscription: https://www.open-mpi.org/mailman/listinfo.cgi/users > Link to this post: > http://www.open-mpi.org/community/lists/users/2016/06/29549.php
