the TCG emulation of QEMU does work without allocatr_pgste. vm.allocate_pgste=1 is necessary to use the KVM kernel module (which is used by qemu in kvm mode)
The main difference is that this uses 4k page tables instead of 2k page tables on s390. So enabling pgstes will increase the page table overhead. The difference is usually pretty small, but might become noticeable when you have things like a big database with hundreds of processes accessing a big area of shared memory. Maybe something like # cat /etc/modprobe.d/99-kvm.conf install kvm /sbin/sysctl vm.allocate_pgste=1; /sbin/modprobe --ignore-install kvm remove kvm /sbin/sysctl vm.allocate_pgste=0; /sbin/modprobe -r --ignore-remove kvm would be good enough? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1533646 Title: Could you set vm.allocate_pgste = 1 by default? To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1533646/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
