Messages in this thread | | | Date | Thu, 07 Jul 2011 03:26:14 +0800 | From | Xiao Guangrong <> | Subject | Re: [PATCH v3 16/19] KVM: MMU: lockless walking shadow page table |
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On 07/07/2011 02:08 AM, Marcelo Tosatti wrote:
>> +static void free_pages_rcu(struct rcu_head *head) >> +{ >> + struct kvm_mmu_page *next, *sp; >> + >> + sp = container_of(head, struct kvm_mmu_page, rcu); >> + while (sp) { >> + if (!list_empty(&sp->link)) >> + next = list_first_entry(&sp->link, >> + struct kvm_mmu_page, link); >> + else >> + next = NULL; >> + kvm_mmu_free_page(sp); >> + sp = next; >> + } >> +} > > There is no need for this while loop. >
The while loop is needed, since many shadow pages can be freed together in the rcu context, on commit_zap_page path, we only remove the list head, and the shadow page is still listed.
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