linux-kernel - Re: [PATCH] nohz: Remove tick_nohz_idle_enter_norcu() / tick_nohz_idle_exit

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-prev] [day] [month] [year] [list]

Message-ID: <20111121163745.GA2323@linux.vnet.ibm.com>
Date:	Mon, 21 Nov 2011 08:37:45 -0800
From:	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>
To:	Frederic Weisbecker <fweisbec@...il.com>
Cc:	Josh Triplett <josh@...htriplett.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Ingo Molnar <mingo@...hat.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>
Subject: Re: [PATCH] nohz: Remove tick_nohz_idle_enter_norcu() /
 tick_nohz_idle_exit_norcu()

On Mon, Nov 21, 2011 at 04:23:51PM +0100, Frederic Weisbecker wrote:
> On Sun, Nov 20, 2011 at 09:28:19PM -0800, Paul E. McKenney wrote:
> > On Mon, Nov 21, 2011 at 02:46:58AM +0100, Frederic Weisbecker wrote:
> > > 2011/11/19 Paul E. McKenney <paulmck@...ux.vnet.ibm.com>:
> > > > On Thu, Nov 17, 2011 at 05:03:44PM -0800, Paul E. McKenney wrote:
> > > >> On Thu, Nov 17, 2011 at 12:11:34PM -0800, Josh Triplett wrote:

[ . . . ]

> > 4.	Task A invokes a system call.  If the system-call entry
> > 	code were to again invoke rcu_idle_enter(), then my patch
> > 	is required.  If you check and avoid invoking rcu_idle_enter()
> > 	in this case, then my patch is not required.
> 
> You mean rcu_idle_exit()? So yeah, since we have the tick running
> and thus RCU not in extended QS, we won't call rcu_idle_exit() on syscall
> entry.

OK, then I will drop my patch.  ;-)

							Thanx, Paul

--
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/