tree 09a723b407b0fefb1b05a30b490b8372ec2cf5cf
parent 5d9ca30e96f567b67a36727aa4ebb34911a2b84a
author Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> 1316681916 +0800
committer Avi Kivity <avi@redhat.com> 1324977422 +0200

KVM: MMU: improve write flooding detected

Detecting write-flooding does not work well, when we handle page written, if
the last speculative spte is not accessed, we treat the page is
write-flooding, however, we can speculative spte on many path, such as pte
prefetch, page synced, that means the last speculative spte may be not point
to the written page and the written page can be accessed via other sptes, so
depends on the Accessed bit of the last speculative spte is not enough

Instead of detected page accessed, we can detect whether the spte is accessed
after it is written, if the spte is not accessed but it is written frequently,
we treat is not a page table or it not used for a long time

Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Signed-off-by: Avi Kivity <avi@redhat.com>