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From: Ingo Molnar <mingo@elte.hu>
To: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: linux-kernel@vger.kernel.org, anton@samba.org,
	akpm@linux-foundation.org, dipankar@in.ibm.com,
	manfred@colorfullife.com, cl@linux-foundation.org,
	josht@linux.vnet.ibm.com, schamp@sgi.com, niv@us.ibm.com,
	dvhltc@us.ibm.com, ego@in.ibm.com, laijs@cn.fujitsu.com,
	rostedt@goodmis.org, peterz@infradead.org,
	penberg@cs.helsinki.fi, andi@firstfloor.org, tglx@linutronix.de
Subject: Re: [PATCH 0/3] v2 Make hierarchical RCU less IPI-happy and add more tracing
Date: Tue, 14 Apr 2009 11:34:41 +0200	[thread overview]
Message-ID: <20090414093441.GA3558@elte.hu> (raw)
In-Reply-To: <1239683478419-git-send-email->


* Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:

> This three-patch set fixes a hierarchical-RCU performance bug 
> located by Anton Blanchard.  This bug affects certain high-end 
> floating-point computation-heavy workloads with closely spaced 
> barrier-synchronized iterations, where an interruption of any one 
> CPU's processing during a given iteration slows the system as a 
> whole.  This bug manifests itself as excessive resched IPIs, and 
> is strictly a performance regression. It does not affect 
> correctness.
> 
> The first patch provides the fix for the problem, the second patch 
> adds the tracing, and the third patch adds the documentation for 
> the tracing.
> 
> Located-by: Anton Blanchard <anton@au1.ibm.com>
> Tested-by: Anton Blanchard <anton@au1.ibm.com>
> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

i've applied the first patch to tip:core/urgent (for .30) and the 
second and third one to tip:core/rcu (for .31).

Thanks Paul,

	Ingo

      parent reply	other threads:[~2009-04-14  9:35 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-04-14  4:31 [PATCH 0/3] v2 Make hierarchical RCU less IPI-happy and add more tracing Paul E. McKenney
2009-04-14  4:31 ` [PATCH 1/3] v2 Make hierarchical RCU less IPI-happy Paul E. McKenney
2009-04-14 10:00   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-04-14  4:31 ` [PATCH 2/3] v2 Add __rcu_pending tracing to hierarchical RCU Paul E. McKenney
2009-04-14 10:00   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-04-14  4:31 ` [PATCH 3/3] v2 Update RCU tracing documentation for __rcu_pending Paul E. McKenney
2009-04-14 10:01   ` [tip:core/rcu] rcu: " tip-bot for Paul E. McKenney
2009-04-14  9:34 ` Ingo Molnar [this message]

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