Home » Mailing list archives » linux-kernel » 2008 » September » 29

[GIT pull] timer fixes for .27

Previous thread: [patch 1/2] revert: x86: move prefill_possible_map calling early, fix by Chuck Ebbert on Monday, September 29, 2008 - 6:27 pm. (3 messages)

Next thread: Linux 2.6.27-rc8 by Linus Torvalds on Monday, September 29, 2008 - 6:39 pm. (40 messages)
[view original message]
From: Thomas Gleixner <tglx@...>
To: Linus Torvalds <torvalds@...>
Cc: Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>, Paul E. McKenney <paulmck@...>
Subject: [GIT pull] timer fixes for .27
Date: Monday, September 29, 2008 - 6:15 pm

Linus,


Please pull the latest timers-fixes-for-linus git tree from:


   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timers-fixes-for-linus


The patches fix hard to trigger bugs in the CPU offline code of

hrtimers which were noticed by Paul McKenney recently. In the worst

case they can leave migrated hrtimers in a stale state.


 Thanks,


	tglx


------------------>

Thomas Gleixner (4):

      hrtimer: migrate pending list on cpu offline

      hrtimer: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimers

      hrtimer: mark migration state

      hrtimer: prevent migration of per CPU hrtimers


 include/linux/hrtimer.h      |   18 ++++++--

 kernel/hrtimer.c             |   95 +++++++++++++++++++++++++++++++++++++----

 kernel/sched.c               |    4 +-

 kernel/time/tick-sched.c     |    2 +-

 kernel/trace/trace_sysprof.c |    2 +-

 5 files changed, 103 insertions(+), 18 deletions(-)


diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h

index 6d93dce..2f245fe 100644

--- a/include/linux/hrtimer.h

+++ b/include/linux/hrtimer.h

@@ -47,14 +47,22 @@ enum hrtimer_restart {

  *	HRTIMER_CB_IRQSAFE:		Callback may run in hardirq context

  *	HRTIMER_CB_IRQSAFE_NO_RESTART:	Callback may run in hardirq context and

  *					does not restart the timer

- *	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:	Callback must run in hardirq context

- *					Special mode for tick emultation

+ *	HRTIMER_CB_IRQSAFE_PERCPU:	Callback must run in hardirq context

+ *					Special mode for tick emulation and

+ *					scheduler timer. Such timers are per

+ *					cpu and not allowed to be migrated on

+ *					cpu unplug.

+ *	HRTIMER_CB_IRQSAFE_UNLOCKED:	Callback should run in hardirq context

+ *					with timer->base lock unlocked

+ *					used for timers which call wakeup to

+ *					avoid lock order problems with rq->lock

  */

 enum hrtimer_cb_mode {

 	HRTIMER_CB_SOFTIRQ,

 	HRTIMER_CB_IRQSAFE,

 	HRTIMER_CB_IRQSAFE_NO_RESTART,

-	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,

+	HRTIMER_CB_IRQSAFE_PE...
[ message continues ]
[view original message]
From: Linus Torvalds <torvalds@...>
To: Thomas Gleixner <tglx@...>
Cc: Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>, Paul E. McKenney <paulmck@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Tuesday, September 30, 2008 - 10:34 am

Did you forget to push? The tip of that branch is still commit

1eda81495a49a4ee91d8863b0a441a624375efea ("x86: prevent stale state of

c1e_mask ...") which I already pulled last week.


		Linus

--
[view original message]
From: Ingo Molnar <mingo@...>
To: Linus Torvalds <torvalds@...>
Cc: Thomas Gleixner <tglx@...>, Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Paul E. McKenney <paulmck@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Tuesday, September 30, 2008 - 11:16 am

hm, i just re-ran the pushout script - see below.


	Ingo


--------->

Linus,


Please pull the latest timers-fixes-for-linus git tree from:


   git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git timers-fixes-for-linus


 Thanks,


	Ingo


------------------>

Thomas Gleixner (4):

      hrtimer: migrate pending list on cpu offline

      hrtimer: fix migration of CB_IRQSAFE_NO_SOFTIRQ hrtimers

      hrtimer: mark migration state

      hrtimer: prevent migration of per CPU hrtimers


 include/linux/hrtimer.h      |   18 ++++++--

 kernel/hrtimer.c             |   95 +++++++++++++++++++++++++++++++++++++----

 kernel/sched.c               |    4 +-

 kernel/time/tick-sched.c     |    2 +-

 kernel/trace/trace_sysprof.c |    2 +-

 5 files changed, 103 insertions(+), 18 deletions(-)


diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h

index 6d93dce..2f245fe 100644

--- a/include/linux/hrtimer.h

+++ b/include/linux/hrtimer.h

@@ -47,14 +47,22 @@ enum hrtimer_restart {

  *	HRTIMER_CB_IRQSAFE:		Callback may run in hardirq context

  *	HRTIMER_CB_IRQSAFE_NO_RESTART:	Callback may run in hardirq context and

  *					does not restart the timer

- *	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:	Callback must run in hardirq context

- *					Special mode for tick emultation

+ *	HRTIMER_CB_IRQSAFE_PERCPU:	Callback must run in hardirq context

+ *					Special mode for tick emulation and

+ *					scheduler timer. Such timers are per

+ *					cpu and not allowed to be migrated on

+ *					cpu unplug.

+ *	HRTIMER_CB_IRQSAFE_UNLOCKED:	Callback should run in hardirq context

+ *					with timer->base lock unlocked

+ *					used for timers which call wakeup to

+ *					avoid lock order problems with rq->lock

  */

 enum hrtimer_cb_mode {

 	HRTIMER_CB_SOFTIRQ,

 	HRTIMER_CB_IRQSAFE,

 	HRTIMER_CB_IRQSAFE_NO_RESTART,

-	HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,

+	HRTIMER_CB_IRQSAFE_PERCPU,

+	HRTIMER_CB_IRQSAFE_UNLOCKED,

 };


 /*

@@ -67,9 +75,10 @@ enum hrtimer_cb_mode {

  * 0x02		callbac...
[ message continues ]
[view original message]
From: Paul E. McKenney <paulmck@...>
To: Thomas Gleixner <tglx@...>
Cc: Linus Torvalds <torvalds@...>, Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Monday, September 29, 2008 - 6:44 pm

Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

--
[view original message]
From: Benjamin Herrenschmidt <benh@...>
To: <paulmck@...>
Cc: Thomas Gleixner <tglx@...>, Linus Torvalds <torvalds@...>, Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Monday, September 29, 2008 - 11:41 pm

Ah, so we found and fixed these ?


Linus, those bugs are actually a regression from when we didn't use the

new timer code (which isn't that long ago). It would be nice to have the

fixes in .27 (and thus in the various distros that will derive from it)

but I would understand if the size of the patch made you choke that late

in the -rc cycle... In which case we'll be in for more backports :-)


Cheers,

Ben.


--
[view original message]
From: Paul E. McKenney <paulmck@...>
To: Benjamin Herrenschmidt <benh@...>
Cc: Thomas Gleixner <tglx@...>, Linus Torvalds <torvalds@...>, Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Monday, September 29, 2008 - 11:54 pm

For "we" == Thomas, yes.  ;-)


--
[view original message]
From: Paul E. McKenney <paulmck@...>
To: Benjamin Herrenschmidt <benh@...>
Cc: Thomas Gleixner <tglx@...>, Linus Torvalds <torvalds@...>, Andrew Morton <akpm@...>, LKML <linux-kernel@...>, Ingo Molnar <mingo@...>
Subject: Re: [GIT pull] timer fixes for .27
Date: Tuesday, September 30, 2008 - 12:02 am

One other thing -- these bugs affect x86 as well as Power.  Just takes

more stress for x86 to see the bugs in some cases.


--
Previous thread: [patch 1/2] revert: x86: move prefill_possible_map calling early, fix by Chuck Ebbert on Monday, September 29, 2008 - 6:27 pm. (3 messages)

Next thread: Linux 2.6.27-rc8 by Linus Torvalds on Monday, September 29, 2008 - 6:39 pm. (40 messages)