linux-kernel - Re: [PATCH] context_tracking: New context tracking susbsystem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <1354179992.2499.35.camel@ThinkPad-T5421.cn.ibm.com>
Date:	Thu, 29 Nov 2012 17:06:32 +0800
From:	Li Zhong <zhong@...ux.vnet.ibm.com>
To:	Frederic Weisbecker <fweisbec@...il.com>
Cc:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	"H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...nel.org>,
	Peter Zijlstra <peterz@...radead.org>,
	Steven Rostedt <rostedt@...dmis.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Gilad.Ben-Yossef.gilad@...yossef.com
Subject: Re: [PATCH] context_tracking: New context tracking susbsystem

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. */


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/