Message ID | 20120621175238.705e6188.yoshikawa.takuya@oss.ntt.co.jp |
---|---|
State | New, archived |
Headers | show |
On Thu, 21 Jun 2012 17:52:38 +0900 Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> wrote: ... > + /* Handle the first one even if idx == idx_end. */ > + do { > + ret |= handler(kvm, rmapp++, data); > + } while (++idx < idx_end); This is unclear and... maybe wrong. I will change this as follows: --- hva_start = max(start, memslot->userspace_addr); hva_end = min(end, memslot->userspace_addr + (memslot->npages << PAGE_SHIFT)); if (hva_start >= hva_end) continue; /* * { gfn(page) | page intersects with [hva_start, hva_end) } * = [gfn_start, gfn_end). */ gfn_start = hva_to_gfn_memslot(hva_start, memslot); gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE-1, memslot); for (j = PT_PAGE_TABLE_LEVEL; j < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++j) { unsigned long idx, idx_end; unsigned long *rmapp; /* * { idx(page_j) | page_j intersects with [hva_start, hva_end) } * = [idx, idx_end]. */ idx = gfn_to_index(gfn_start, memslot->base_gfn, j); idx_end = gfn_to_index(gfn_end - 1, memslot->base_gfn, j); rmapp = __gfn_to_rmap(gfn_start, j, memslot); for (; idx <= idx_end; ++idx) { ret |= handler(kvm, rmapp++, data); } } --- This way, much clearly, we can handle exactly same rmaps as before. I also need to change ppc code as well in patch 3. Thanks, Takuya -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 306711a..462becb 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1192,16 +1192,15 @@ static int kvm_handle_hva_range(struct kvm *kvm, unsigned long data)) { int j; - int ret; - int retval = 0; + int ret = 0; struct kvm_memslots *slots; struct kvm_memory_slot *memslot; slots = kvm_memslots(kvm); kvm_for_each_memslot(memslot, slots) { - gfn_t gfn; unsigned long hva_start, hva_end; + gfn_t gfn_start, gfn_end; hva_start = max(start, memslot->userspace_addr); hva_end = min(end, memslot->userspace_addr + @@ -1209,25 +1208,27 @@ static int kvm_handle_hva_range(struct kvm *kvm, if (hva_start >= hva_end) continue; - for (gfn = hva_to_gfn_memslot(hva_start, memslot); - gfn < hva_to_gfn_memslot(hva_end, memslot); gfn++) { - ret = 0; + gfn_start = hva_to_gfn_memslot(hva_start, memslot); + gfn_end = hva_to_gfn_memslot(hva_end, memslot); - for (j = PT_PAGE_TABLE_LEVEL; - j < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++j) { - unsigned long *rmapp; + for (j = PT_PAGE_TABLE_LEVEL; + j < PT_PAGE_TABLE_LEVEL + KVM_NR_PAGE_SIZES; ++j) { + unsigned long idx, idx_end; + unsigned long *rmapp; - rmapp = __gfn_to_rmap(gfn, j, memslot); - ret |= handler(kvm, rmapp, data); - } - trace_kvm_age_page(memslot->userspace_addr + - (gfn - memslot->base_gfn) * PAGE_SIZE, - memslot, ret); - retval |= ret; + idx = gfn_to_index(gfn_start, memslot->base_gfn, j); + idx_end = gfn_to_index(gfn_end, memslot->base_gfn, j); + + rmapp = __gfn_to_rmap(gfn_start, j, memslot); + + /* Handle the first one even if idx == idx_end. */ + do { + ret |= handler(kvm, rmapp++, data); + } while (++idx < idx_end); } } - return retval; + return ret; } static int kvm_handle_hva(struct kvm *kvm, unsigned long hva,
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. Note: in the new code we could not use trace_kvm_age_page(), so we just dropped the point from kvm_handle_hva_range(). Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> --- arch/x86/kvm/mmu.c | 39 ++++++++++++++++++++------------------- 1 files changed, 20 insertions(+), 19 deletions(-)