From patchwork Tue Feb 10 14:41:48 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rik van Riel X-Patchwork-Id: 5807851 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 2D03A9F36A for ; Tue, 10 Feb 2015 14:44:39 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 61D0520115 for ; Tue, 10 Feb 2015 14:44:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8003E2010C for ; Tue, 10 Feb 2015 14:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964799AbbBJOl7 (ORCPT ); Tue, 10 Feb 2015 09:41:59 -0500 Received: from shelob.surriel.com ([74.92.59.67]:40257 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756194AbbBJOl5 (ORCPT ); Tue, 10 Feb 2015 09:41:57 -0500 Received: from [2002:4a5c:3b41:1:224:e8ff:fe38:995c] (helo=annuminas.surriel.com) by shelob.surriel.com with esmtps (TLSv1:AES256-SHA:256) (Exim 4.63) (envelope-from ) id 1YLC0f-0001oE-Ag; Tue, 10 Feb 2015 09:41:53 -0500 Received: from annuminas.surriel.com (localhost.localdomain [127.0.0.1]) by annuminas.surriel.com (8.14.8/8.14.5) with ESMTP id t1AEfrie024742; Tue, 10 Feb 2015 09:41:53 -0500 Received: (from riel@localhost) by annuminas.surriel.com (8.14.8/8.14.8/Submit) id t1AEfrOl024741; Tue, 10 Feb 2015 09:41:53 -0500 X-Authentication-Warning: annuminas.surriel.com: riel set sender to riel@redhat.com using -f From: riel@redhat.com To: paulmck@linux.vnet.ibm.com Cc: will.deacon@arm.com, linux-kernel@vger.kernel.org, Catalin.Marinas@arm.com, fweisbec@gmail.com, kvm@vger.kernel.org, mtosatti@redhat.com, borntraeger@de.ibm.com, mingo@kernel.org, oleg@redhat.com, lcapitulino@redhat.com, pbonzini@redhat.com Subject: [PATCH 4/6] rcu, nohz: run vtime_user_enter/exit only when state == IN_USER Date: Tue, 10 Feb 2015 09:41:48 -0500 Message-Id: <1423579310-24555-5-git-send-email-riel@redhat.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1423579310-24555-1-git-send-email-riel@redhat.com> References: <1423579310-24555-1-git-send-email-riel@redhat.com> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Rik van Riel Only run vtime_user_enter, vtime_user_exit, and the user enter & exit trace points when we are entering or exiting user state, respectively. The KVM code in guest_enter and guest_exit already take care of calling vtime_guest_enter and vtime_guest_exit, respectively. The RCU code only distinguishes between "idle" and "not idle or kernel". There should be no need to add an additional (unused) state there. Signed-off-by: Rik van Riel --- kernel/context_tracking.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index 38e38aeac8b9..0e4e318d5ea4 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -77,7 +77,6 @@ void context_tracking_enter(enum ctx_state state) local_irq_save(flags); if ( __this_cpu_read(context_tracking.state) != state) { if (__this_cpu_read(context_tracking.active)) { - trace_user_enter(0); /* * At this stage, only low level arch entry code remains and * then we'll run in userspace. We can assume there won't be @@ -85,7 +84,10 @@ void context_tracking_enter(enum ctx_state state) * user_exit() or rcu_irq_enter(). Let's remove RCU's dependency * on the tick. */ - vtime_user_enter(current); + if (state == IN_USER) { + trace_user_enter(0); + vtime_user_enter(current); + } rcu_user_enter(); } /* @@ -143,8 +145,10 @@ void context_tracking_exit(enum ctx_state state) * RCU core about that (ie: we may need the tick again). */ rcu_user_exit(); - vtime_user_exit(current); - trace_user_exit(0); + if (state == IN_USER) { + vtime_user_exit(current); + trace_user_exit(0); + } } __this_cpu_write(context_tracking.state, IN_KERNEL); }