diff options
| author | Avi Kivity <avi@redhat.com> | 2012-05-14 15:44:06 +0300 |
|---|---|---|
| committer | Marcelo Tosatti <mtosatti@redhat.com> | 2012-05-16 16:08:28 -0300 |
| commit | c142786c6291189b5c85f53d91743e1eefbd8fe0 (patch) | |
| tree | 80e5e37a29ae247d6223672126a10c15751f4dc7 /arch/x86/include | |
| parent | b2da15ac26a0c00fc0d399a2bc5cf3c4e15f0b4f (diff) | |
| download | linux-c142786c6291189b5c85f53d91743e1eefbd8fe0.tar.gz linux-c142786c6291189b5c85f53d91743e1eefbd8fe0.tar.xz linux-c142786c6291189b5c85f53d91743e1eefbd8fe0.zip | |
KVM: MMU: Don't use RCU for lockless shadow walking
Using RCU for lockless shadow walking can increase the amount of memory
in use by the system, since RCU grace periods are unpredictable. We also
have an unconditional write to a shared variable (reader_counter), which
isn't good for scaling.
Replace that with a scheme similar to x86's get_user_pages_fast(): disable
interrupts during lockless shadow walk to force the freer
(kvm_mmu_commit_zap_page()) to wait for the TLB flush IPI to find the
processor with interrupts enabled.
We also add a new vcpu->mode, READING_SHADOW_PAGE_TABLES, to prevent
kvm_flush_remote_tlbs() from avoiding the IPI.
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 4 |
1 files changed, 0 insertions, 4 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 69e39bc7e36f..64c8989263f6 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -240,8 +240,6 @@ struct kvm_mmu_page { #endif int write_flooding_count; - - struct rcu_head rcu; }; struct kvm_pio_request { @@ -540,8 +538,6 @@ struct kvm_arch { u64 hv_guest_os_id; u64 hv_hypercall; - atomic_t reader_counter; - #ifdef CONFIG_KVM_MMU_AUDIT int audit_point; #endif |