From: Avi Kivity Date: Mon, 23 Jul 2007 15:33:14 +0000 (+0300) Subject: Revert "KVM: Avoid useless memory write when possible" X-Git-Tag: MMI-PSA29.97-13-9~41160^2~2 X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7cfa4b0a43286b1da3afa4f5f99d52e65a8f30fc;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git Revert "KVM: Avoid useless memory write when possible" This reverts commit a3c870bdce4d34332ebdba7eb9969592c4c6b243. While it does save useless updates, it (probably) defeats the fork detector, causing a massive performance loss. Signed-off-by: Avi Kivity --- diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 46efbe70801c..a8d8db8e3ccb 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -1070,10 +1070,8 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa, return 0; mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT); virt = kmap_atomic(page, KM_USER0); - if (memcmp(virt + offset_in_page(gpa), val, bytes)) { - kvm_mmu_pte_write(vcpu, gpa, virt + offset, val, bytes); - memcpy(virt + offset_in_page(gpa), val, bytes); - } + kvm_mmu_pte_write(vcpu, gpa, virt + offset, val, bytes); + memcpy(virt + offset_in_page(gpa), val, bytes); kunmap_atomic(virt, KM_USER0); return 1; }