From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760954AbbBIQFB (ORCPT ); Mon, 9 Feb 2015 11:05:01 -0500 Received: from shelob.surriel.com ([74.92.59.67]:48002 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933518AbbBIQE6 (ORCPT ); Mon, 9 Feb 2015 11:04:58 -0500 From: riel@redhat.com To: paulmck@linux.vnet.ibm.com Cc: linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@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, Rik van Riel Subject: [PATCH 3/6] rcu,nohz: run vtime_user_enter/exit only when state == IN_USER Date: Mon, 9 Feb 2015 11:04:41 -0500 Message-Id: <1423497884-21615-4-git-send-email-riel@redhat.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1423497884-21615-1-git-send-email-riel@redhat.com> References: <1423497884-21615-1-git-send-email-riel@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 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 e031e8c0fb91..2d94147c07b2 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(); } /* @@ -137,8 +139,10 @@ 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); } -- 1.9.3