I've noticed on a number of my systems that after shutting down my application that uses huge pages that I'm left with some pages still in HugePages_Rsvd. It is possible that I still have something using huge pages that I'm not aware of but so far my attempts to find anything using huge pages have failed. I've run some simple tests using map_hugetlb.c from the kernel source and can see that pages that have been reserved but not allocated still show up in /proc/<pid>/smaps and /proc/<pid>/numa_maps. Are there any cases where this is not true? [root@dev106 ~]# grep HugePages /proc/meminfo AnonHugePages: 241664 kB HugePages_Total: 512 HugePages_Free: 512 HugePages_Rsvd: 384 HugePages_Surp: 0 Hugepagesize: 2048 kB [root@dev106 ~]# grep "KernelPageSize:.*2048" /proc/*/smaps [root@dev106 ~]# grep "VmFlags:.*ht" /proc/*/smaps [root@dev106 ~]# grep huge /proc/*/numa_maps [root@dev106 ~]# grep Huge /proc/meminfo AnonHugePages: 241664 kB HugePages_Total: 512 HugePages_Free: 512 HugePages_Rsvd: 384 HugePages_Surp: 0 Hugepagesize: 2048 kB So here I have 384 pages reserved and I can't find anything that is using them. This is on a machine running 3.14.33. I can possibly try running a newer kernel if there is a belief that this has been fixed. I'm also happy to provide more information or try some debug patches if there are ideas on how to track this down. I'm not entirely sure how hard this is to reproduce but nearly every machine I've looked at is in this state so it must not be too hard. Thanks, Shawn -- 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>