[PATCH 0/2] Faster MMU lookups for Book3s v3

Marcelo Tosatti mtosatti at redhat.com
Fri Jul 2 01:40:29 EST 2010


On Wed, Jun 30, 2010 at 03:18:44PM +0200, Alexander Graf wrote:
> Book3s suffered from my really bad shadow MMU implementation so far. So
> I finally got around to implement a combined hash and list mechanism that
> allows for much faster lookup of mapped pages.
> 
> To show that it really is faster, I tried to run simple process spawning
> code inside the guest with and without these patches:
> 
> [without]
> 
> debian-powerpc:~# time for i in {1..1000}; do /bin/echo hello > /dev/null; done
> 
> real    0m20.235s
> user    0m10.418s
> sys     0m9.766s
> 
> [with]
> 
> debian-powerpc:~# time for i in {1..1000}; do /bin/echo hello > /dev/null; done
> 
> real    0m14.659s
> user    0m8.967s
> sys     0m5.688s
> 
> So as you can see, performance improved significantly.
> 
> v2 -> v3:
> 
>   - use hlist
>   - use global slab cache
> 
> Alexander Graf (2):
>   KVM: PPC: Add generic hpte management functions
>   KVM: PPC: Make use of hash based Shadow MMU
> 
>  arch/powerpc/include/asm/kvm_book3s.h |    9 +
>  arch/powerpc/include/asm/kvm_host.h   |   17 ++-
>  arch/powerpc/kvm/Makefile             |    2 +
>  arch/powerpc/kvm/book3s.c             |   14 ++-
>  arch/powerpc/kvm/book3s_32_mmu_host.c |  104 ++-----------
>  arch/powerpc/kvm/book3s_64_mmu_host.c |   98 +-----------
>  arch/powerpc/kvm/book3s_mmu_hpte.c    |  277 +++++++++++++++++++++++++++++++++
>  7 files changed, 331 insertions(+), 190 deletions(-)
>  create mode 100644 arch/powerpc/kvm/book3s_mmu_hpte.c

Applied, thanks.



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