Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754201Ab2K2KaW (ORCPT ); Thu, 29 Nov 2012 05:30:22 -0500 Received: from mail-la0-f46.google.com ([209.85.215.46]:62167 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760Ab2K2KaV (ORCPT ); Thu, 29 Nov 2012 05:30:21 -0500 MIME-Version: 1.0 In-Reply-To: <1354179992.2499.35.camel@ThinkPad-T5421.cn.ibm.com> References: <1354041205-6989-1-git-send-email-fweisbec@gmail.com> <1354179992.2499.35.camel@ThinkPad-T5421.cn.ibm.com> Date: Thu, 29 Nov 2012 11:30:19 +0100 Message-ID: Subject: Re: [PATCH] context_tracking: New context tracking susbsystem From: Frederic Weisbecker To: Li Zhong Cc: "Paul E. McKenney" , LKML , Andrew Morton , "H. Peter Anvin" , Ingo Molnar , Peter Zijlstra , Steven Rostedt , Thomas Gleixner , Gilad.Ben-Yossef.gilad@benyossef.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2207 Lines: 60 2012/11/29 Li Zhong : > On Tue, 2012-11-27 at 19:33 +0100, Frederic Weisbecker wrote: > [....] >> - >> - WARN_ON_ONCE(!current->mm); >> - >> - local_irq_save(flags); >> - rdtp = &__get_cpu_var(rcu_dynticks); >> - if (!rdtp->ignore_user_qs && !rdtp->in_user) { >> - rdtp->in_user = true; >> - rcu_eqs_enter(true); >> - } > > It seems to me that ignore_user_qs and in_user defined in struct > rcu_dynticks are no longer needed? > > If so, then maybe we could remove them, code below: > > ========== > diff --git a/kernel/rcutree.c b/kernel/rcutree.c > index e441b77..b8fae5d 100644 > --- a/kernel/rcutree.c > +++ b/kernel/rcutree.c > @@ -2719,9 +2719,6 @@ rcu_boot_init_percpu_data(int cpu, struct rcu_state *rsp) > rdp->dynticks = &per_cpu(rcu_dynticks, cpu); > WARN_ON_ONCE(rdp->dynticks->dynticks_nesting != DYNTICK_TASK_EXIT_IDLE); > WARN_ON_ONCE(atomic_read(&rdp->dynticks->dynticks) != 1); > -#ifdef CONFIG_RCU_USER_QS > - WARN_ON_ONCE(rdp->dynticks->in_user); > -#endif > rdp->cpu = cpu; > rdp->rsp = rsp; > rcu_boot_init_nocb_percpu_data(rdp); > diff --git a/kernel/rcutree.h b/kernel/rcutree.h > index 4b69291..6f21f2e 100644 > --- a/kernel/rcutree.h > +++ b/kernel/rcutree.h > @@ -102,10 +102,6 @@ struct rcu_dynticks { > /* idle-period nonlazy_posted snapshot. */ > int tick_nohz_enabled_snap; /* Previously seen value from sysfs. */ > #endif /* #ifdef CONFIG_RCU_FAST_NO_HZ */ > -#ifdef CONFIG_RCU_USER_QS > - bool ignore_user_qs; /* Treat userspace as extended QS or not */ > - bool in_user; /* Is the CPU in userland from RCU POV? */ > -#endif > }; > > /* RCU's kthread states for tracing. */ > > Good point. Paul, do you prefer to fold these changes into my patch or do we add a new one? In any case Li we need your Signed-off-by tag. Thanks. -- 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/