On Thu 21-03-13 10:33:07, Simon Jeons wrote: > Hi Mel, > On 03/21/2013 02:19 AM, Mel Gorman wrote: > >The following problem was reported against a distribution kernel when > >zone_reclaim was enabled but the same problem applies to the mainline > >kernel. The reproduction case was as follows > > > >1. Run numactl -m +0 dd if=largefile of=/dev/null > > This allocates a large number of clean pages in node 0 > > I confuse why this need allocate a large number of clean pages? It reads from file and puts pages into the page cache. The pages are not modified so they are clean. Output file is /dev/null so no pages are written. dd doesn't call fadvise(POSIX_FADV_DONTNEED) on the input file by default so pages from the file stay in the page cache -- Michal Hocko SUSE Labs -- 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/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>