1. 13 6月, 2017 1 次提交
    • M
      s390/kvm: avoid global config of vm.alloc_pgste=1 · 23fefe11
      Martin Schwidefsky 提交于
      The system control vm.alloc_pgste is used to control the size of the
      page tables, either 2K or 4K. The idea is that a KVM host sets the
      vm.alloc_pgste control to 1 which causes *all* new processes to run
      with 4K page tables. For a non-kvm system the control should stay off
      to save on memory used for page tables.
      
      Trouble is that distributions choose to set the control globally to
      be able to run KVM guests. This wastes memory on non-KVM systems.
      
      Introduce the PT_S390_PGSTE ELF segment type to "mark" the qemu
      executable with it. All executables with this (empty) segment in
      its ELF phdr array will be started with 4K page tables. Any executable
      without PT_S390_PGSTE will run with the default 2K page tables.
      
      This removes the need to set vm.alloc_pgste=1 for a KVM host and
      minimizes the waste of memory for page tables.
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      23fefe11
  2. 12 6月, 2017 38 次提交
  3. 08 6月, 2017 1 次提交