One thing that came up when discussing with SMB as an obvious "uses mem more in a kernel" are the structures needed per POSSIBLE cpu.
Comparing the system that I downgraded I found from [1]: With the -kvm kernel before: kernel: setup_percpu: NR_CPUS:64 nr_cpumask_bits:1 nr_cpu_ids:1 nr_node_ids:1 kernel: rcu: RCU restricting CPUs from NR_CPUS=64 to nr_cpu_ids=1. With the -generic kernel: kernel: setup_percpu: NR_CPUS:8192 nr_cpumask_bits:1 nr_cpu_ids:1 nr_node_ids:1 kernel: rcu: RCU restricting CPUs from NR_CPUS=8192 to nr_cpu_ids=1. So let us try the new 6.3 generic kernel, but with kernel parameter maxcpus=1 possible_cpus=1 nr_cpus=1 ^^ this might be too hard, but ok for testing That gives me: kernel: setup_percpu: NR_CPUS:8192 nr_cpumask_bits:1 nr_cpu_ids:1 nr_node_ids:1 But sadly, the memory does not look much better: root@m-new:~# cat /proc/meminfo MemTotal: 956176 kB MemFree: 640960 kB MemAvailable: 664816 kB Was a good idea, but sadly that wasn't it. And the initial NR_CPUS is a compile time parameter which we can not tune down :-/ [1]: https://github.com/torvalds/linux/blob/master/arch/x86/kernel/setup_percpu.c#L122 -- 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/2032933 Title: Mantic (23.10) minimal images increase in memory consumption, port usage and processes running Status in cloud-images: Confirmed Status in linux package in Ubuntu: Confirmed Bug description: The Mantic (Ubuntu 23.10) images are undergoing some big changes prior to 23.10 release in October. This is a devel release so this is the perfect time to be making these changes but we are noticing some changes that were not expected. This bug is to track the unexpected changes and discuss/resolve these. The changes that have been made to mantic minimal: * Move to the linux-generic kernel from the linux-kvm kernel * This also involved removal of the virtio-blk driver, which is the default for QEMU and OpenStack, but this is being restored in an upcoming 6.5 mantic kernel and is being trakced @ https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2030745 * Move to using minimal-cloud seed - see https://ubuntu-archive-team.ubuntu.com/seeds/ubuntu.mantic/cloud-minimal * No longer installing Recommends packages * No initramfs fallback for boot - only initramfsless boot The latest mantic minimal images are available @ http://cloud- images.ubuntu.com/minimal/daily/mantic/ and are also available in the public clouds. A package name manifest diff can be seen @ https://pastebin.ubuntu.com/p/rRd6STnNmK/ We have had reports of higher memory usage on an idle system, higher number of ports open on an idle system and higher number of process running on a idle system. To help with debugging I have built and uploaded the following images and package manifests to https://people.canonical.com/~philroche/20230824-manticl-minimal- LP2032933/ * 20230618-before-kernel-change-before-seed-change-mantic-minimal-cloudimg-amd64 * Before kernel change and before seed change * 20230824-after-kernel-change-before-seed-change-mantic-minimal-cloudimg-amd64 * After kernel change and before seed change * 20230821.1-after-kernel-change-after-seed-change-mantic-minimal-cloudimg-amd64 * After kernel change and after seed change To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/2032933/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
