From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 205C3C7618F for ; Fri, 26 Jul 2019 19:19:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EFA4A218B8 for ; Fri, 26 Jul 2019 19:19:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388734AbfGZTTk (ORCPT ); Fri, 26 Jul 2019 15:19:40 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:50197 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388562AbfGZTS7 (ORCPT ); Fri, 26 Jul 2019 15:18:59 -0400 Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hr5k1-0001Ay-HV; Fri, 26 Jul 2019 21:18:57 +0200 Message-Id: <20190726185753.363363474@linutronix.de> User-Agent: quilt/0.65 Date: Fri, 26 Jul 2019 20:30:55 +0200 From: Thomas Gleixner To: LKML Cc: x86@kernel.org, Steven Rostedt , Sebastian Siewior , Anna-Maria Gleixner , Paolo Bonzini , Arnaldo Carvalho de Melo , Jiri Olsa , Juergen Gross Subject: [patch 07/12] KVM: LAPIC: Mark hrtimer to expire in hard interrupt context References: <20190726183048.982726647@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sebastian Andrzej Siewior On PREEMPT_RT enabled kernels unmarked hrtimers are moved into soft interrupt expiry mode by default. While that's not a functional requirement for the KVM local APIC timer emulation, it's a latency issue which can be avoided by marking the timer so hard interrupt context expiry is enforced. No functional change. [ tglx: Split out from larger combo patch. Add changelog. ] Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Cc: kvm@vger.kernel.org Cc: Paolo Bonzini --- arch/x86/kvm/lapic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -2302,7 +2302,7 @@ int kvm_create_lapic(struct kvm_vcpu *vc apic->vcpu = vcpu; hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC, - HRTIMER_MODE_ABS); + HRTIMER_MODE_ABS_HARD); apic->lapic_timer.timer.function = apic_timer_fn; if (timer_advance_ns == -1) { apic->lapic_timer.timer_advance_ns = LAPIC_TIMER_ADVANCE_ADJUST_INIT;