On 2016年03月10日 23:26, Paolo Bonzini wrote: > > > On 10/03/2016 15:40, Xiao Guangrong wrote: >> long dirty_count = kvm->tlbs_dirty; >> >> + /* >> + * read tlbs_dirty before doing tlb flush to make sure not tlb >> request is >> + * lost. >> + */ >> smp_mb(); >> + >> if (kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH)) >> ++kvm->stat.remote_tlb_flush; >> cmpxchg(&kvm->tlbs_dirty, dirty_count, 0); >> >> >> Any comment? > > Compared to smp_load_acquire(), smp_mb() adds an ordering between stores > and loads. Is the > > The load of kvm->tlbs_dirty should then be > > /* > * Read tlbs_dirty before setting KVM_REQ_TLB_FLUSH in > * kvm_make_all_cpus_request. This > */ > long dirty_count = smp_load_acquire(kvm->tlbs_dirty); > > Tianyu, I think Xiao provided the information that I was missing. Would > you like to prepare the patch? Paolo: Sure. I will do that. Guangrong: Thanks a lot for your input. -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
