On Tue, 16 May 2017 15:15:23 -0700
Anthony Xu <anthony...@intel.com> wrote:
> If cpu-memory address space is same as memory address space,
> use memory address space for cpu-memory address space.
>
> any memory region change causeaddress space to rebuild PhysPageMap,
> rebuilding PhysPageMap is very expensive.
>
> removing cpu-memory address space reduces the guest boot time and
> memory usage.
>
> Signed-off-by: Anthony Xu <anthony...@intel.com>
> ---
> cpus.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/cpus.c b/cpus.c
> index 740b8dc..15c7a6a 100644
> --- a/cpus.c
> +++ b/cpus.c
> @@ -1748,8 +1748,13 @@ void qemu_init_vcpu(CPUState *cpu)
> /* If the target cpu hasn't set up any address spaces itself,
> * give it the default one.
> */
> - AddressSpace *as = address_space_init_shareable(cpu->memory,
> - "cpu-memory");
> + AddressSpace *as;
> + if (cpu->memory == address_space_memory.root) {
> + address_space_memory.ref_count++;
probably this would cause reference leak when vcpu is destroyed
> + as = &address_space_memory;
> + } else {
> + as = address_space_init_shareable(cpu->memory, "cpu-memory");
> + }
> cpu->num_ases = 1;
> cpu_address_space_init(cpu, as, 0);
> }
