------- Comment From [email protected] 2017-10-26 01:24 EDT------- We do support 16GB hugepage from hardware point of view. What we had missing was the ability to allocate such large contiguous memory in the kernel. The pseries platform solved this by taking help from hypervisor. PAPR introduced a mechanism for hypervisor to mark 16G contiguous region reserved and pass the details via device tree. On Powernv this is not available and hence we are not able to make use of 16G hugepages.
I have added the ability to allocate 16G hugepages on powernv platform. The relevant fixes can be found at commit 4ae279c2c96ab38a78b954d218790a8f6db714e5 Author: Aneesh Kumar K.V <[email protected]> Date: Fri Jul 28 10:31:27 2017 +0530 powerpc/mm/hugetlb: Allow runtime allocation of 16G. You may want that and other dependent kernel patches. -aneesh -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1706247 Title: It should not be possible to turn on 16g huge pages on Ubuntu 16.04.2 PowerNV Status in The Ubuntu-power-systems project: Triaged Status in linux package in Ubuntu: Triaged Bug description: 16G Huge Pages are not supported on PowerNV (bare metal) installations. Ubuntu 16.04.2 still allows 16G huge pages to be turned on. Contact Information = Mike Hollinger ([email protected]) ---uname output--- Linux aprilmin4 4.4.0-83-generic #106-Ubuntu SMP Mon Jun 26 17:53:54 UTC 2017 ppc64le ppc64le ppc64le GNU/Linux Machine Type = 8335-GTB ---Debugger--- A debugger is not configured ---Steps to Reproduce--- 1. Add the following to the kernel boot args (either via editing the petitboot boot option manually, or updating /boot/grub/grub.cfg: default_hugepagesz=16G hugepagesz=16G hugepages=4 2. Boot Linux 3. Observe that the kernel believes 16G huge pages are available: ubuntu@aprilmin7:~$ cat /proc/meminfo | grep -i huge AnonHugePages: 475136 kB HugePages_Total: 0 HugePages_Free: 0 HugePages_Rsvd: 0 HugePages_Surp: 0 Hugepagesize: 16777216 kB ubuntu@aprilmin7:~$ ls /sys/devices/system/node/node0/hugepages hugepages-1024kB hugepages-16384kB hugepages-16777216kB Stack trace output: no Oops output: no System Dump Info: The system is not configured to capture a system dump. *Additional Instructions for Mike Hollinger ([email protected]): -Post a private note with access information to the machine that the bug is occuring on. -Attach sysctl -a output output to the bug. This may be recreated on any bare metal POWER8 server with Ubuntu 16.04.2; I haven't checked other versions of Ubuntu. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu-power-systems/+bug/1706247/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
