From patchwork Tue Feb 10 14:41:46 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: 5807821 Return-Path: X-Original-To: patchwork-kvm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id AC3BFBF440 for ; Tue, 10 Feb 2015 14:43:47 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BC89420115 for ; Tue, 10 Feb 2015 14:43:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D85C52010C for ; Tue, 10 Feb 2015 14:43:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964901AbbBJOmA (ORCPT ); Tue, 10 Feb 2015 09:42:00 -0500 Received: from shelob.surriel.com ([74.92.59.67]:40241 "EHLO shelob.surriel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756110AbbBJOl5 (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-0001oA-2V; 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 t1AEfqiA024734; Tue, 10 Feb 2015 09:41:53 -0500 Received: (from riel@localhost) by annuminas.surriel.com (8.14.8/8.14.8/Submit) id t1AEfq7E024733; Tue, 10 Feb 2015 09:41:52 -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 2/6] rcu, nohz: add state parameter to context_tracking_enter/exit Date: Tue, 10 Feb 2015 09:41:46 -0500 Message-Id: <1423579310-24555-3-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 Add the expected ctx_state as a parameter to context_tracking_enter and context_tracking_exit, allowing the same functions to not just track kernel <> user space switching, but also kernel <> guest transitions. Signed-off-by: Rik van Riel --- include/linux/context_tracking.h | 10 +++++----- kernel/context_tracking.c | 14 +++++++------- 2 files changed, 12 insertions(+), 12 deletions(-) diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h index 03b9c733eae7..954253283709 100644 --- a/include/linux/context_tracking.h +++ b/include/linux/context_tracking.h @@ -10,8 +10,8 @@ #ifdef CONFIG_CONTEXT_TRACKING extern void context_tracking_cpu_set(int cpu); -extern void context_tracking_enter(void); -extern void context_tracking_exit(void); +extern void context_tracking_enter(enum ctx_state state); +extern void context_tracking_exit(enum ctx_state state); extern void context_tracking_user_enter(void); extern void context_tracking_user_exit(void); extern void __context_tracking_task_switch(struct task_struct *prev, @@ -37,7 +37,7 @@ static inline enum ctx_state exception_enter(void) return 0; prev_ctx = this_cpu_read(context_tracking.state); - context_tracking_user_exit(); + context_tracking_exit(prev_ctx); return prev_ctx; } @@ -45,8 +45,8 @@ static inline enum ctx_state exception_enter(void) static inline void exception_exit(enum ctx_state prev_ctx) { if (context_tracking_is_enabled()) { - if (prev_ctx == IN_USER) - context_tracking_user_enter(); + if (prev_ctx != IN_KERNEL) + context_tracking_enter(prev_ctx); } } diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c index bbdc423936e6..38e38aeac8b9 100644 --- a/kernel/context_tracking.c +++ b/kernel/context_tracking.c @@ -47,7 +47,7 @@ void context_tracking_cpu_set(int cpu) * instructions to execute won't use any RCU read side critical section * because this function sets RCU in extended quiescent state. */ -void context_tracking_enter(void) +void context_tracking_enter(enum ctx_state state) { unsigned long flags; @@ -75,7 +75,7 @@ void context_tracking_enter(void) WARN_ON_ONCE(!current->mm); local_irq_save(flags); - if ( __this_cpu_read(context_tracking.state) != IN_USER) { + if ( __this_cpu_read(context_tracking.state) != state) { if (__this_cpu_read(context_tracking.active)) { trace_user_enter(0); /* @@ -101,7 +101,7 @@ void context_tracking_enter(void) * OTOH we can spare the calls to vtime and RCU when context_tracking.active * is false because we know that CPU is not tickless. */ - __this_cpu_write(context_tracking.state, IN_USER); + __this_cpu_write(context_tracking.state, state); } local_irq_restore(flags); } @@ -109,7 +109,7 @@ NOKPROBE_SYMBOL(context_tracking_enter); void context_tracking_user_enter(void) { - context_tracking_enter(); + context_tracking_enter(IN_USER); } NOKPROBE_SYMBOL(context_tracking_user_enter); @@ -125,7 +125,7 @@ NOKPROBE_SYMBOL(context_tracking_user_enter); * This call supports re-entrancy. This way it can be called from any exception * handler without needing to know if we came from userspace or not. */ -void context_tracking_exit(void) +void context_tracking_exit(enum ctx_state state) { unsigned long flags; @@ -136,7 +136,7 @@ void context_tracking_exit(void) return; local_irq_save(flags); - if (__this_cpu_read(context_tracking.state) == IN_USER) { + if (__this_cpu_read(context_tracking.state) == state) { if (__this_cpu_read(context_tracking.active)) { /* * We are going to run code that may use RCU. Inform @@ -154,7 +154,7 @@ NOKPROBE_SYMBOL(context_tracking_exit); void context_tracking_user_exit(void) { - context_tracking_exit(); + context_tracking_exit(IN_USER); } NOKPROBE_SYMBOL(context_tracking_user_exit);