tree d8814c9fbf17570a1cbed823b2dea7468fe9c1d9
parent f395302e09ef783b8f82d1160510a95aa8c66dbc
author Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> 1341219573 +0900
committer Marcelo Tosatti <mtosatti@redhat.com> 1342641304 -0300

KVM: MMU: Avoid handling same rmap_pde in kvm_handle_hva_range()

When we invalidate a THP page, we call the handler with the same
rmap_pde argument 512 times in the following loop:

  for each guest page in the range
    for each level
      unmap using rmap

This patch avoids these extra handler calls by changing the loop order
like this:

  for each level
    for each rmap in the range
      unmap using rmap

With the preceding patches in the patch series, this made THP page
invalidation more than 5 times faster on our x86 host: the host became
more responsive during swapping the guest's memory as a result.

Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>