From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-x229.google.com (mail-ob0-x229.google.com [IPv6:2607:f8b0:4003:c01::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (not verified)) by ozlabs.org (Postfix) with ESMTPS id 6FE982C0091 for ; Tue, 5 Nov 2013 18:42:15 +1100 (EST) Received: by mail-ob0-f169.google.com with SMTP id uz6so8290246obc.28 for ; Mon, 04 Nov 2013 23:42:12 -0800 (PST) From: Liu Ping Fan To: linuxppc-dev@lists.ozlabs.org, kvm-ppc@vger.kernel.org Subject: [PATCH 1/3] powerpc/kvm: simplify the entering logic for secondary thread Date: Tue, 5 Nov 2013 15:42:42 +0800 Message-Id: <1383637364-14691-1-git-send-email-pingfank@linux.vnet.ibm.com> Cc: Paul Mackerras , Alexander Graf List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , After the primary vcpu changes vcore_state to VCORE_RUNNING, there is very little chance to schedule to secondary vcpu. So if we change the code sequence around set vcore_state to VCORE_RUNNING and disable preemption, we lost little. But we simplify the entering logi, based on the fact that if primary vcpu runs, the secondary vcpu can not be scheduled. Signed-off-by: Liu Ping Fan --- arch/powerpc/kvm/book3s_hv.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c index 62a2b5a..38b1fc0 100644 --- a/arch/powerpc/kvm/book3s_hv.c +++ b/arch/powerpc/kvm/book3s_hv.c @@ -1222,8 +1222,8 @@ static void kvmppc_run_core(struct kvmppc_vcore *vc) kvmppc_create_dtl_entry(vcpu, vc); } - vc->vcore_state = VCORE_RUNNING; preempt_disable(); + vc->vcore_state = VCORE_RUNNING; spin_unlock(&vc->lock); kvm_guest_enter(); @@ -1351,12 +1351,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu) * this thread straight away and have it join in. */ if (!signal_pending(current)) { - if (vc->vcore_state == VCORE_RUNNING && - VCORE_EXIT_COUNT(vc) == 0) { - vcpu->arch.ptid = vc->n_runnable - 1; - kvmppc_create_dtl_entry(vcpu, vc); - kvmppc_start_thread(vcpu); - } else if (vc->vcore_state == VCORE_SLEEPING) { + if (vc->vcore_state == VCORE_SLEEPING) { wake_up(&vc->wq); } -- 1.8.1.4