Sorry for late, please see online. From: Huang, Marvin [mailto:Marvin.Huang@windriver.com] Sent: Friday, April 26, 2019 12:17 AM To: Sun, Austin <austin.sun@intel.com> Cc: starlingx-discuss@lists.starlingx.io Subject: RE: questions about '[Feature] Huge page management' https://storyboard.openstack.org/#!/story/2004763 Hi Austin, Thanks for your information! So given 'This feature is enable K8S feature-gate as describe in [1]': 1 How to tell if this 'hugepage feature' is (currently) enabled or disabled? Any user visible signs in Horizon, CLIs outputs? Or it's transparent to users? Or: a. Is it only reflected in arguments to 'kubeadm init --feature-gates='...,hugepage=enable/disable', which is called to provision a node/master? [Austin] the default hugepage is false, and can be enabled by /etc/sysconfig/kubelet for node. b. And/or (also) is shown in /var/lib/kubelet/config.yaml, e.g.: controller-0:~$ grep 'featureGate' /var/lib/kubelet/config.yaml -A2 featureGates: HugePages: false [Austin] this is default setting . c. Any OS level options changes, like options inside /etc/default/grub? [Austin] As Story describe , disable 1G hugepage grub if vswitch_type is none . 2 Can changing label enable or/and disable the 'hugepage feature'? For example, now assuming worker compute-0 has label 'openstack-compute-node', hence hugepage is disabled: a. We can remove the label 'openstack-compute-node ' using CLI system host-label-remove compute-0 openstack-compute-node b. What the expected the system behavior after the label is removed? The 'hugepage feature' will be enabled after been unlocked, which can be verified using methods [Austin] If label is removed, and unlock, the hugepage should be disabled 3 Any user aware difference between the features enabled/disabled? [Austin] end user may not aware the difference. This will be used for some k8s application. Thanks! Marvin From: Sun, Austin [mailto:austin.sun@intel.com] Sent: Wednesday, April 24, 2019 9:55 PM To: Huang, Marvin Cc: starlingx-discuss@lists.starlingx.io<mailto:starlingx-discuss@lists.starlingx.io> Subject: RE: questions about '[Feature] Huge page management' https://storyboard.openstack.org/#!/story/2004763 Hi, Marvin: This feature is not directly related with "system host-memory-modify" function, user still should be able to modify mem config as before. This feature is enable K8S feature-gate as describe in [1]. And K8S enabling hugepage feature is opposite to compute label ( means compute label is tagged, then k8s hugepage feature is disabled (false), if compute label is not tagged , then k8s hugepage is enabled ) About your question about VM hugepage decrease, I did not dig into VM mem , so I cannot give more comments. [1] https://kubernetes.io/docs/reference/command-line-tools-reference/feature-ga... Thanks. BR Austin Sun. From: Huang, Marvin [mailto:Marvin.Huang@windriver.com] Sent: Thursday, April 25, 2019 4:33 AM To: Sun, Austin <austin.sun@intel.com<mailto:austin.sun@intel.com>> Cc: starlingx-discuss@lists.starlingx.io<mailto:starlingx-discuss@lists.starlingx.io> Subject: questions about '[Feature] Huge page management' https://storyboard.openstack.org/#!/story/2004763 Hi Austin, According to (Storyboard) 2004763<https://storyboard.openstack.org/%23!/story/2004763>, I know that you're working on the feature "Huge page management". I've some questions about the feature. Though one of its 2 tasks is still in Review (the other is shown merged), you might now have the answers already. In the description of the Story, there are requirement: "- Enable k8s huge page feature for worker nodes that do not have the openstack compute label. It should be disabled otherwise." Questions: what is this meaning to users? By 'Enable', is it meaning users can modify memory allocation on the node? (via the following): system host-modify <worker-name> [-2M <2M hugepages number>] [-1G <1G hugepages number>] [-f <function>] ... or Horizon: Admin -> Platform -> Host Inventory ... Otherwise ('disabled'), the CLIs (system host-memory-xxx) will reject any requests? Or the corresponding Horizon pages do not have any items to update the memory application? Or those were disabled? "- Automatically defaults for worker nodes with openstack compute label. Changes will be applied on the unlock. - Current 2M huge page default settings - 1-1G huge page per numa node for vswitch " Questions: in this situation, is the k8s huge page feature disabled (according to the above requirement)? And the (host-memory) CLIs will reject any requests? And a question related with VMs: If a VM using huge page (with flavor having 'hw:mem_page_size=large' or 'hw:mem_page_size=1048576') is launched, will the free memory pages decreased accordingly on the worker it's running on? That is, if the VM is consuming 1G huge-page, the number of free page of 1G size on the hosting worker should be reduced by 1. Is this still the expected behavior? This is the assumption in https://bugs.launchpad.net/starlingx/+bug/1813325. Regards, Marvin