[PATCH 4/4] KVM: Optimize dirty logging by rmap_write_protect()

2011-11-14 Thread Takuya Yoshikawa
Currently, write protecting a slot needs to walk all the shadow pages and checks ones which have a pte mapping a page in it. The walk is overly heavy when dirty pages in that slot are not so many and checking the shadow pages would result in unwanted cache pollution. To mitigate this problem, we

Re: [PATCH 4/4] KVM: Optimize dirty logging by rmap_write_protect()

2011-11-14 Thread Avi Kivity
On 11/14/2011 11:24 AM, Takuya Yoshikawa wrote: Currently, write protecting a slot needs to walk all the shadow pages and checks ones which have a pte mapping a page in it. The walk is overly heavy when dirty pages in that slot are not so many and checking the shadow pages would result in

Re: [PATCH 4/4] KVM: Optimize dirty logging by rmap_write_protect()

2011-11-14 Thread Takuya Yoshikawa
(2011/11/14 19:22), Avi Kivity wrote: + * + * Generally speaking, if there are not so many dirty pages compared to the + * number of shadow pages, we should use the latter. + * + * Note that letting others write into a page marked dirty in the old bitmap + * by using the remaining tlb entry is