As outlined in the past conceptually there is nothing that qemu can do. The kernel can in theory get memory zeroing to become concurrent and thereby scale with CPUs but that is an effort that was already started twice and didn't get into the kernel yet.
Workarounds are known to shrink that size massively (HP). Also this is nothing the kernel Team would usually "do" they would follow upstream on it, so I'm leaving it open but low for them. I realized those discussions where going on but not linked here. => https://lore.kernel.org/lkml/20181105165558.11698-1-daniel.m.jor...@oracle.com/T/ => https://lwn.net/Articles/728023/ => https://blogs.oracle.com/linux/making-kernel-tasks-faster-with-ktask,-an-update Is one example. I'd ask the kernel Team to keep an eye open for that, be encouraging in discussions. This really has a huge benefit in those use cases. ** Changed in: linux (Ubuntu) Importance: Medium => Low ** Changed in: qemu (Ubuntu) Status: Triaged => Invalid -- 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/1838575 Title: passthrough devices cause >17min boot delay Status in linux package in Ubuntu: Confirmed Status in qemu package in Ubuntu: Invalid Bug description: Adding passthrough devices to a guest introduces a boot delay of > 17 minutes. During this time libvirt reports the guest to be "paused". The delay does not seem to scale with the # of hostdevs - that is, 1 hostdev causes about a 17min delay, while 16 only bumps that up to ~18min. Removing all hostdevs avoids the delay. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1838575/+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
