Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754076AbbBEXze (ORCPT ); Thu, 5 Feb 2015 18:55:34 -0500 Received: from e36.co.us.ibm.com ([32.97.110.154]:51989 "EHLO e36.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751486AbbBEXzd (ORCPT ); Thu, 5 Feb 2015 18:55:33 -0500 Date: Thu, 5 Feb 2015 15:55:26 -0800 From: "Paul E. McKenney" To: riel@redhat.com Cc: kvm@vger.kernel.org, borntraeger@de.ibm.com, linux-kernel@vger.kernel.org, mtosatti@redhat.com, mingo@kernel.orgm, ak@linux.intel.com, oleg@redhat.com, masami.hiramatsu.pt@hitachi.com, fweisbec@gmail.com, lcapitulino@redhat.com, pbonzini@redhat.com Subject: Re: [PATCH 1/5] rcu,nohz: add state parameter to context_tracking_user_enter/exit Message-ID: <20150205235526.GQ5370@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1423167832-17609-1-git-send-email-riel@redhat.com> <1423167832-17609-2-git-send-email-riel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1423167832-17609-2-git-send-email-riel@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15020523-0021-0000-0000-000008561037 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4333 Lines: 122 On Thu, Feb 05, 2015 at 03:23:48PM -0500, riel@redhat.com wrote: > From: Rik van Riel > > Add the expected ctx_state as a parameter to context_tracking_user_enter > and context_tracking_user_exit, allowing the same functions to not just > track kernel <> user space switching, but also kernel <> guest transitions. > > Signed-off-by: Rik van Riel Acked-by: Paul E. McKenney > --- > include/linux/context_tracking.h | 12 ++++++------ > kernel/context_tracking.c | 10 +++++----- > 2 files changed, 11 insertions(+), 11 deletions(-) > > diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h > index 37b81bd51ec0..bd9f000fc98d 100644 > --- a/include/linux/context_tracking.h > +++ b/include/linux/context_tracking.h > @@ -10,21 +10,21 @@ > #ifdef CONFIG_CONTEXT_TRACKING > extern void context_tracking_cpu_set(int cpu); > > -extern void context_tracking_user_enter(void); > -extern void context_tracking_user_exit(void); > +extern void context_tracking_user_enter(enum ctx_state state); > +extern void context_tracking_user_exit(enum ctx_state state); > extern void __context_tracking_task_switch(struct task_struct *prev, > struct task_struct *next); > > static inline void user_enter(void) > { > if (context_tracking_is_enabled()) > - context_tracking_user_enter(); > + context_tracking_user_enter(IN_USER); > > } > static inline void user_exit(void) > { > if (context_tracking_is_enabled()) > - context_tracking_user_exit(); > + context_tracking_user_exit(IN_USER); > } > > static inline enum ctx_state exception_enter(void) > @@ -35,7 +35,7 @@ static inline enum ctx_state exception_enter(void) > return 0; > > prev_ctx = this_cpu_read(context_tracking.state); > - context_tracking_user_exit(); > + context_tracking_user_exit(prev_ctx); > > return prev_ctx; > } > @@ -44,7 +44,7 @@ static inline void exception_exit(enum ctx_state prev_ctx) > { > if (context_tracking_is_enabled()) { > if (prev_ctx == IN_USER) > - context_tracking_user_enter(); > + context_tracking_user_enter(prev_ctx); > } > } > > diff --git a/kernel/context_tracking.c b/kernel/context_tracking.c > index 937ecdfdf258..4c010787c9ec 100644 > --- a/kernel/context_tracking.c > +++ b/kernel/context_tracking.c > @@ -47,7 +47,7 @@ void context_tracking_cpu_set(int cpu) > * to execute won't use any RCU read side critical section because this > * function sets RCU in extended quiescent state. > */ > -void context_tracking_user_enter(void) > +void context_tracking_user_enter(enum ctx_state state) > { > unsigned long flags; > > @@ -75,7 +75,7 @@ void context_tracking_user_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_user_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); > } > @@ -118,7 +118,7 @@ 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_user_exit(void) > +void context_tracking_user_exit(enum ctx_state state) > { > unsigned long flags; > > @@ -129,7 +129,7 @@ void context_tracking_user_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 > -- > 1.9.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/