lkml.org 
[lkml]   [2011]   [Nov]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v2 5/6] KVM: sort memslots by its size and use line search
    On 11/18/2011 11:19 AM, Xiao Guangrong wrote:
    > Sort memslots base on its size and use line search to find it, so the larger
    > memslots have better fit
    >
    > The idea is from Avi
    >
    > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
    > ---
    > include/linux/kvm_host.h | 22 +++++++++---
    > virt/kvm/kvm_main.c | 82 ++++++++++++++++++++++++++++++++-------------
    > 2 files changed, 75 insertions(+), 29 deletions(-)
    >
    > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
    > index a0e4d63..83b396a 100644
    > --- a/include/linux/kvm_host.h
    > +++ b/include/linux/kvm_host.h
    > @@ -230,8 +230,12 @@ struct kvm_irq_routing_table {};
    > #define KVM_MEM_SLOTS_NUM (KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS)
    > #endif
    >
    > +/*
    > + * Note:
    > + * memslots are not sorted by id anymore, please use id_to_memslot()
    > + * to get the memslot by its id.
    > + */
    > struct kvm_memslots {
    > - int nmemslots;
    > u64 generation;
    > struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM];
    > };
    > @@ -307,9 +311,10 @@ static inline struct kvm_vcpu *kvm_get_vcpu(struct kvm *kvm, int i)
    > (vcpup = kvm_get_vcpu(kvm, idx)) != NULL; \
    > idx++)
    >
    > -#define kvm_for_each_memslot(slots, memslot, i) \
    > - for (i = 0; i < (slots)->nmemslots && \
    > - ({ memslot = &(slots)->memslots[i]; 1; }); i++)
    > +#define kvm_for_each_memslot(slots, memslot, i) \
    > + for (i = 0; i < KVM_MEM_SLOTS_NUM && \
    > + ({ memslot = &(slots)->memslots[i]; 1; }) && \
    > + memslot->npages != 0; i++)

    You might allocate an always-empty memslot at the end and simplify the
    termination condition.

    >
    > int kvm_vcpu_init(struct kvm_vcpu *vcpu, struct kvm *kvm, unsigned id);
    > void kvm_vcpu_uninit(struct kvm_vcpu *vcpu);
    > @@ -335,7 +340,14 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm)
    > static inline struct kvm_memory_slot *
    > id_to_memslot(struct kvm_memslots *slots, int id)
    > {
    > - return &slots->memslots[id];
    > + int i;
    > +
    > + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
    > + if (slots->memslots[i].id == id)
    > + return &slots->memslots[i];
    > +

    Is that in any hot path? we could make an array for doing this translation.

    Alex wants to increase the memslot count, so this could be a long loop.


    --
    error compiling committee.c: too many arguments to function



    \
     
     \ /
      Last update: 2011-11-20 12:29    [W:0.047 / U:0.480 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site