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* [PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of heavy CPU-hotplug stress
@ 2009-08-15 16:51 Paul E. McKenney
  2009-08-15 16:53 ` [PATCH -tip/core/rcu 1/6] Split hierarchical RCU initialization into boot-time and CPU-online pieces Paul E. McKenney
                   ` (6 more replies)
  0 siblings, 7 replies; 38+ messages in thread
From: Paul E. McKenney @ 2009-08-15 16:51 UTC (permalink / raw)
  To: linux-kernel
  Cc: mingo, laijs, dipankar, josht, akpm, mathieu.desnoyers, dvhltc,
	niv, tglx, peterz, rostedt, hugh.dickins, benh

This patch set provides the following cleanups and fixes for RCU in
workloads that involve lots of CPU hotplugging.  Ingo, please reset
core/rcu to 240ebbf before applying these patches.

o	Split Hierarchical RCU initialization into boot-time and
	CPU-hotplug pieces, so that other CPUs never see the data
	structures in the act of being stitched together.

o	Introduce a cpu_notifier() that works as does the current
	hotcpu_notifier(), but also notifies during boot time even
	if !HOTPLUG_CPU.

o	Make RCU use the new cpu_notifier() to simplify hotplug code
	and reduce the number of notifiers in use.  (This also fixes
	the problem Ingo and Hugh found.)

o	Preemptable RCU had a bug due to its overly clever attempt
	to move counts from CPUs going offline.  This is "unsafe
	at any speed", so remove the cleverness.

o	Since offline CPUs now can have non-zero counts, they must
	now be included in the tracing.

o	Fix typo in preemptable RCU's rcu_irq_enter() comment
	submitted by Josh Triplett.

These pass tests combining rcutorture and continuous CPU-hotplug
operations, in other words, no sleeping between successive CPU-hotplug
operations.  This set does not fix the bug involving deadlocks through
rcutorture, kthread_stop(), and migration threads.  However, this bug
does not affect production systems, so should not stand in the way of
applying these patches.

							Thanx, Paul

 b/include/linux/cpu.h       |   18 +++++++++-----
 b/kernel/rcupdate.c         |   16 ++++++++++++-
 b/kernel/rcupreempt.c       |   25 +-------------------
 b/kernel/rcupreempt_trace.c |    6 ++--
 b/kernel/rcutree.c          |   54 ++++++++++++++++++++++++++------------------
 kernel/rcupreempt.c         |   12 +--------
 kernel/rcutree.c            |   18 ++++----------
 7 files changed, 72 insertions(+), 77 deletions(-)

^ permalink raw reply	[flat|nested] 38+ messages in thread

end of thread, other threads:[~2009-08-21 15:37 UTC | newest]

Thread overview: 38+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2009-08-15 16:51 [PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of heavy CPU-hotplug stress Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 1/6] Split hierarchical RCU initialization into boot-time and CPU-online pieces Paul E. McKenney
2009-08-15 17:07   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 2/6] Introduce cpu_notifier() to handle !HOTPLUG_CPU case Paul E. McKenney
2009-08-15 17:07   ` [tip:core/rcu] cpu hotplug: " tip-bot for Paul E. McKenney
2009-08-17 17:21   ` [PATCH -tip/core/rcu 2/6] " Josh Triplett
2009-08-17 18:28     ` Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 3/6] Simplify RCU CPU-hotplug notification Paul E. McKenney
2009-08-15 17:07   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-08-20  4:02   ` [PATCH -tip/core/rcu 3/6] " Lai Jiangshan
2009-08-20  4:21     ` Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 4/6] Make preemptable RCU scan all CPUs when summing RCU counters Paul E. McKenney
2009-08-15 17:07   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 5/6] Make rcupreempt_trace.c look at offline CPUs Paul E. McKenney
2009-08-15 17:07   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-08-15 16:53 ` [PATCH -tip/core/rcu 6/6] Fix typo in rcu_irq_exit() comment header Paul E. McKenney
2009-08-15 17:00   ` Ingo Molnar
2009-08-15 17:10     ` Paul E. McKenney
2009-08-15 17:11       ` Ingo Molnar
2009-08-15 17:08   ` [tip:core/rcu] rcu: " tip-bot for Josh Triplett
2009-08-17 18:24 ` [PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of heavy CPU-hotplug stress Josh Triplett
2009-08-17 19:20   ` Paul E. McKenney
2009-08-18 15:26     ` Ingo Molnar
2009-08-18 20:07       ` Paul E. McKenney
2009-08-19  6:06         ` Paul E. McKenney
2009-08-19 11:59           ` Ingo Molnar
2009-08-19 12:09           ` [tip:core/rcu] rcu: Delay rcu_barrier() wait until beginning of next CPU-hotunplug operation tip-bot for Paul E. McKenney
2009-08-19 15:24           ` [PATCH -tip/core/rcu 1/6] Cleanups and fixes for RCU in face of heavy CPU-hotplug stress Mathieu Desnoyers
2009-08-19 16:38             ` Paul E. McKenney
2009-08-19 18:10               ` Mathieu Desnoyers
2009-08-19 18:31                 ` Paul E. McKenney
2009-08-20 14:03       ` Mathieu Desnoyers
2009-08-21 14:17         ` Ingo Molnar
2009-08-21 14:29           ` Steven Rostedt
2009-08-21 14:44             ` Ingo Molnar
2009-08-21 15:00               ` Mathieu Desnoyers
2009-08-21 15:37               ` Paul E. McKenney
2009-08-21 14:58           ` Mathieu Desnoyers

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