linux-kernel - Re: [PATCH 2/4 v2] nohz: Split extended quiescent state handling from nohz switch

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

Date:	Mon, 06 Jun 2011 17:16:03 +0200
From:	Hans-Christian Egtvedt <hans-christian.egtvedt@...el.com>
To:	Frederic Weisbecker <fweisbec@...il.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	"Paul E. McKenney" <paulmck@...ux.vnet.ibm.com>,
	Ingo Molnar <mingo@...e.hu>,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Thomas Gleixner <tglx@...utronix.de>,
	"H. Peter Anvin" <hpa@...or.com>,
	Russell King <linux@....linux.org.uk>,
	Mike Frysinger <vapier@...too.org>,
	Ralf Baechle <ralf@...ux-mips.org>,
	Paul Mackerras <paulus@...ba.org>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	Paul Mundt <lethal@...ux-sh.org>,
	David Miller <davem@...emloft.net>,
	Chris Metcalf <cmetcalf@...era.com>,
	Guan Xuetao <gxt@...c.pku.edu.cn>
Subject: Re: [PATCH 2/4 v2] nohz: Split extended quiescent state handling
 from nohz switch

On Mon, 2011-06-06 at 05:20 +0200, Frederic Weisbecker wrote:
> It is assumed that rcu won't be used once we switch to tickless
> mode and until we restart the tick. However this is not always
> true, as in x86-64 where we dereference the idle notifiers after
> the tick is stopped.
> 
> To prepare for fixing this, split the tickless mode switching and
> RCU extended quiescent state logics.
> Make tick_nohz_stop/restart_sched_tick() RCU agnostic but provide
> a new pair of APIs tick_nohz_enter/exit_idle() that keep the
> old behaviour by handling both the nohz mode and RCU extended
> quiescent states, then convert every archs to use these.
> 
> Archs that want to switch to extended QS to some custom points
> can do it later by using tick_nohz_stop_sched_tick() and
> rcu_enter_nohz() seperately.
> 
> v2: Remove rcu_exit_nohz() from tick_nohz_restart_sched_tick()
> 
> Signed-off-by: Frederic Weisbecker <fweisbec@...il.com>
> Cc: Paul E. McKenney <paulmck@...ux.vnet.ibm.com>
> Cc: Ingo Molnar <mingo@...e.hu>
> Cc: Peter Zijlstra <a.p.zijlstra@...llo.nl>
> Cc: Thomas Gleixner <tglx@...utronix.de>
> Cc: H. Peter Anvin <hpa@...or.com>
> Cc: Russell King <linux@....linux.org.uk>
> Cc: Hans-Christian Egtvedt <hans-christian.egtvedt@...el.com>
> Cc: Mike Frysinger <vapier@...too.org>
> Cc: Ralf Baechle <ralf@...ux-mips.org>
> Cc: Paul Mackerras <paulus@...ba.org>
> Cc: Heiko Carstens <heiko.carstens@...ibm.com>
> Cc: Paul Mundt <lethal@...ux-sh.org>
> Cc: David Miller <davem@...emloft.net>
> Cc: Chris Metcalf <cmetcalf@...era.com>
> Cc: Guan Xuetao <gxt@...c.pku.edu.cn>

<snipp>

>  arch/avr32/kernel/process.c            |    4 +-

For the AVR32 related bits

Acked-by: Hans-Christian Egtvedt <hans-christian.egtvedt@...el.com>

<snipp>

-- 
Hans-Christian Egtvedt

--
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/