[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] When flush tlb , we need consider the cpu_online_map
When flush tlb mask, we need consider the cpu_online_map. The same happens to ept flush also. We noticed sometime system hang on cpu online/offline stress test. The reason is because flush_tlb_mask from __get_page_type is deadloop. This should be caused by a small windows in cpu offline. The cpu_online_map is changed and the interrupt is disabled at take_cpu_down() for the to-be-offline CPU. However, the __sync_lazy_execstate() called from idle_task_exit() in the idle_loop() for the to-be-offline CPU. At that time, the stop_machine_run is finished already, and __get_page_type may be called in other CPU before the __sync_lazy_execstate(). BTW, I noticed that cpu_clear(cpu, cpu_online_map) is called twice in __cpu_disable, I will ask the owner which one should be removed. Signed-off-by: Jiang, Yunhong <yunhong.jiang@xxxxxxxxx> diff -r f3db0ae08304 xen/arch/x86/hvm/vmx/vmx.c --- a/xen/arch/x86/hvm/vmx/vmx.c Sat Mar 27 16:01:35 2010 +0000 +++ b/xen/arch/x86/hvm/vmx/vmx.c Mon Mar 29 17:49:51 2010 +0800 @@ -1235,6 +1235,9 @@ void ept_sync_domain(struct domain *d) * unnecessary extra flushes, to avoid allocating a cpumask_t on the stack. */ d->arch.hvm_domain.vmx.ept_synced = d->domain_dirty_cpumask; + cpus_and(d->arch.hvm_domain.vmx.ept_synced, + d->arch.hvm_domain.vmx.ept_synced, + cpu_online_map); on_selected_cpus(&d->arch.hvm_domain.vmx.ept_synced, __ept_sync_domain, d, 1); } diff -r f3db0ae08304 xen/arch/x86/smp.c --- a/xen/arch/x86/smp.c Sat Mar 27 16:01:35 2010 +0000 +++ b/xen/arch/x86/smp.c Mon Mar 29 17:47:25 2010 +0800 @@ -229,6 +229,7 @@ void flush_area_mask(const cpumask_t *ma { spin_lock(&flush_lock); cpus_andnot(flush_cpumask, *mask, *cpumask_of(smp_processor_id())); + cpus_and(flush_cpumask, cpu_online_map, flush_cpumask); flush_va = va; flush_flags = flags; send_IPI_mask(&flush_cpumask, INVALIDATE_TLB_VECTOR); Attachment:
flush_tlb_onlinemap.patch _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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