From patchwork Fri Dec 13 06:07:21 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Takuya Yoshikawa X-Patchwork-Id: 300898 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 9846A2C00A6 for ; Fri, 13 Dec 2013 17:03:43 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751874Ab3LMGDm (ORCPT ); Fri, 13 Dec 2013 01:03:42 -0500 Received: from tama50.ecl.ntt.co.jp ([129.60.39.147]:34861 "EHLO tama50.ecl.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751872Ab3LMGDm (ORCPT ); Fri, 13 Dec 2013 01:03:42 -0500 Received: from mfs6.rdh.ecl.ntt.co.jp (mfs6.rdh.ecl.ntt.co.jp [129.60.39.149]) by tama50.ecl.ntt.co.jp (8.13.8/8.13.8) with ESMTP id rBD63eQK014354; Fri, 13 Dec 2013 15:03:40 +0900 Received: from mfs6.rdh.ecl.ntt.co.jp (localhost.localdomain [127.0.0.1]) by mfs6.rdh.ecl.ntt.co.jp (Postfix) with ESMTP id 94C78E0132; Fri, 13 Dec 2013 15:03:40 +0900 (JST) Received: from imail2.m.ecl.ntt.co.jp (imail2.m.ecl.ntt.co.jp [129.60.5.247]) by mfs6.rdh.ecl.ntt.co.jp (Postfix) with ESMTP id 89184E0131; Fri, 13 Dec 2013 15:03:40 +0900 (JST) Received: from yshpad ([129.60.241.119]) by imail2.m.ecl.ntt.co.jp (8.13.8/8.13.8) with SMTP id rBD63e7f028303; Fri, 13 Dec 2013 15:03:40 +0900 Date: Fri, 13 Dec 2013 15:07:21 +0900 From: Takuya Yoshikawa To: kvm@vger.kernel.org Cc: kvm-ppc@vger.kernel.org Subject: [PATCH 1/2] KVM: Use cond_resched() directly and remove useless kvm_resched() Message-Id: <20131213150721.ea310a8e.yoshikawa_takuya_b1@lab.ntt.co.jp> X-Mailer: Sylpheed 3.1.0 (GTK+ 2.24.4; x86_64-pc-linux-gnu) Mime-Version: 1.0 X-TM-AS-MML: No Sender: kvm-ppc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm-ppc@vger.kernel.org Since the commit 15ad7146 ("KVM: Use the scheduler preemption notifiers to make kvm preemptible"), the remaining stuff in this function is a simple cond_resched() call with an extra need_resched() check which was there to avoid dropping VCPUs unnecessarily. Now it is meaningless. Signed-off-by: Takuya Yoshikawa --- arch/ia64/kvm/kvm-ia64.c | 2 +- arch/powerpc/kvm/book3s_hv.c | 2 +- arch/x86/kvm/x86.c | 2 +- include/linux/kvm_host.h | 1 - virt/kvm/kvm_main.c | 8 -------- 5 files changed, 3 insertions(+), 12 deletions(-) diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c index 985bf80..53f44be 100644 --- a/arch/ia64/kvm/kvm-ia64.c +++ b/arch/ia64/kvm/kvm-ia64.c @@ -702,7 +702,7 @@ again: out: srcu_read_unlock(&vcpu->kvm->srcu, idx); if (r > 0) { - kvm_resched(vcpu); + cond_resched(); idx = srcu_read_lock(&vcpu->kvm->srcu); goto again; } diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 072287f..3fa99b2 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1348,7 +1348,7 @@ static void kvmppc_run_core(struct kvmppc_vcore *vc) kvm_guest_exit(); preempt_enable(); - kvm_resched(vcpu); + cond_resched(); spin_lock(&vc->lock); now = get_tb(); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 5d004da..21748bb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6089,7 +6089,7 @@ static int __vcpu_run(struct kvm_vcpu *vcpu) } if (need_resched()) { srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx); - kvm_resched(vcpu); + cond_resched(); vcpu->srcu_idx = srcu_read_lock(&kvm->srcu); } } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9523d2a..4ecf107 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -583,7 +583,6 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu); void kvm_vcpu_kick(struct kvm_vcpu *vcpu); bool kvm_vcpu_yield_to(struct kvm_vcpu *target); void kvm_vcpu_on_spin(struct kvm_vcpu *vcpu); -void kvm_resched(struct kvm_vcpu *vcpu); void kvm_load_guest_fpu(struct kvm_vcpu *vcpu); void kvm_put_guest_fpu(struct kvm_vcpu *vcpu); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4f588bc..3a33c98 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1710,14 +1710,6 @@ void kvm_vcpu_kick(struct kvm_vcpu *vcpu) EXPORT_SYMBOL_GPL(kvm_vcpu_kick); #endif /* !CONFIG_S390 */ -void kvm_resched(struct kvm_vcpu *vcpu) -{ - if (!need_resched()) - return; - cond_resched(); -} -EXPORT_SYMBOL_GPL(kvm_resched); - bool kvm_vcpu_yield_to(struct kvm_vcpu *target) { struct pid *pid;