Messages in this thread Patch in this message | | | From | Avi Kivity <> | Subject | [PATCH 10/19] KVM: mmu_shrink: kvm_mmu_zap_page requires slots_lock to be held | Date | Tue, 15 Jul 2008 15:12:29 +0300 |
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From: Marcelo Tosatti <mtosatti@redhat.com>
kvm_mmu_zap_page() needs slots lock held (rmap_remove->gfn_to_memslot, for example).
Since kvm_lock spinlock is held in mmu_shrink(), do a non-blocking down_read_trylock().
Untested.
Signed-off-by: Avi Kivity <avi@qumranet.com> --- arch/x86/kvm/mmu.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 1fd8e3b..ff7cf63 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1987,6 +1987,8 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) list_for_each_entry(kvm, &vm_list, vm_list) { int npages; + if (!down_read_trylock(&kvm->slots_lock)) + continue; spin_lock(&kvm->mmu_lock); npages = kvm->arch.n_alloc_mmu_pages - kvm->arch.n_free_mmu_pages; @@ -1999,6 +2001,7 @@ static int mmu_shrink(int nr_to_scan, gfp_t gfp_mask) nr_to_scan--; spin_unlock(&kvm->mmu_lock); + up_read(&kvm->slots_lock); } if (kvm_freed) list_move_tail(&kvm_freed->vm_list, &vm_list); -- 1.5.6.1
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