Re: [PATCH] kvm swapping with mmu notifiers + age_page

[Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>]

Andrea Arcangeli wrote:
> This is the same as before but it uses the age_page callback to
> prevent the guest OS working set to be swapped out. It works well here
> so far. This depends on the memslot locking with mmu lock patch and on
> the mmu notifiers #v3 patch that I'll post in CC with linux-mm shortly
> that implements the age_page callback and that changes follow_page to
> set the young bit in the pte instead of setting the referenced bit (so
> the age_page will be called again later when the VM clears the young
> bit).
>
>  
> +static void unmap_spte(struct kvm *kvm, u64 *spte)
> +{
> +	struct page *page = pfn_to_page((*spte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT);
> +	get_page(page);
> +	rmap_remove(kvm, spte);
> +	set_shadow_pte(spte, shadow_trap_nonpresent_pte);
> +	kvm_flush_remote_tlbs(kvm);
> +	__free_page(page);
> +}
>   

Why is get_page()/__free_page() needed here? Isn't kvm_release_page_*() 
sufficient?


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


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