From: Peter Zijlstra <peterz@infradead.org>
To: paulmck@linux.vnet.ibm.com
Cc: Thomas Gleixner <tglx@linutronix.de>,
"Luck, Tony" <tony.luck@intel.com>,
"Yu, Fenghua" <fenghua.yu@intel.com>,
Rusty Russell <rusty@rustcorp.com.au>,
Ingo Molnar <mingo@elte.hu>, H Peter Anvin <hpa@zytor.com>,
"Siddha, Suresh B" <suresh.b.siddha@intel.com>,
"Mallick, Asit K" <asit.k.mallick@intel.com>,
Arjan Dan De Ven <arjan@linux.intel.com>,
linux-kernel <linux-kernel@vger.kernel.org>, x86 <x86@kernel.org>,
linux-pm <linux-pm@vger.kernel.org>,
"Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
Subject: Re: [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi
Date: Wed, 06 Jun 2012 10:42:55 +0200 [thread overview]
Message-ID: <1338972175.2749.78.camel@twins> (raw)
In-Reply-To: <20120605221240.GW2388@linux.vnet.ibm.com>
On Tue, 2012-06-05 at 15:12 -0700, Paul E. McKenney wrote:
> > RCU has similar nasties.
>
> I am working to rid RCU of this sort of thing. I have rcu_barrier() so
> that it avoids messing with CPUs that don't have callbacks, which will
> be almost all of the idle CPUs, especially for CONFIG_RCU_FAST_NO_HZ=y.
> I believe that I have also removed all of RCU's dependencies on CPU
> hotplug's using kstopmachine, though Murphy would say otherwise.
>
> I still need to fix up synchronize_sched_expedited(), but that is on
> the list. I considered getting rid of this one, but I am probably going
> to have to make synchronize_sched() map to it during boot time to keep
> the boot-speed demons satisfied.
Not the point really. Its perfectly fine for applications in an
'isolated' set to use system calls, hence they get to participate in RCU
state.
I don't think the isolation means userspace while(1) applications is
interesting. Sure, some people do this, and we should dtrt for them, but
the far more interesting case is 'regular' applications that do use
system calls.
next prev parent reply other threads:[~2012-06-06 8:43 UTC|newest]
Thread overview: 73+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-04 18:17 [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi Fenghua Yu
2012-06-04 18:17 ` [PATCH 1/6] x86/Documentation/kernel-parameters.txt: Add wakeup_cpu_via_init kernel parameter help Fenghua Yu
2012-06-04 18:17 ` [PATCH 2/6] x86/head_32.S/head_64.S: Kernel entry code after waking up offline CPU via mwait or nmi Fenghua Yu
2012-06-04 18:17 ` [PATCH 3/6] x86/smpboot.c: Wake " Fenghua Yu
2012-06-04 18:58 ` Suresh Siddha
2012-06-04 19:35 ` Yu, Fenghua
2012-06-04 18:17 ` [PATCH 4/6] x86/apic_flat_64.c: Wakeup function in apic calls mwait or nmi method Fenghua Yu
2012-06-04 18:17 ` [PATCH 5/6] x86/x2apic_cluster.c: Wakeup function in x2apic_cluster " Fenghua Yu
2012-06-04 18:17 ` [PATCH 6/6] x86/x2apic_phys.c: Wakeup function in x2apic_phys " Fenghua Yu
2012-06-04 18:17 ` Fenghua Yu
2012-06-04 20:11 ` [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi Thomas Gleixner
2012-06-04 20:18 ` Luck, Tony
2012-06-04 22:52 ` Thomas Gleixner
2012-06-04 20:33 ` Peter Zijlstra
2012-06-05 0:40 ` Rusty Russell
2012-06-05 1:23 ` Arjan van de Ven
2012-06-05 7:38 ` Peter Zijlstra
2012-06-05 14:17 ` Alan Stern
2012-06-05 15:27 ` Arjan van de Ven
2012-06-05 7:39 ` Peter Zijlstra
2012-06-05 16:02 ` Yu, Fenghua
2012-06-05 16:09 ` Peter Zijlstra
2012-06-05 16:18 ` Yu, Fenghua
2012-06-05 16:19 ` Peter Zijlstra
2012-06-05 17:44 ` Luck, Tony
2012-06-05 17:50 ` Peter Zijlstra
2012-06-05 19:43 ` Thomas Gleixner
2012-06-05 19:45 ` Peter Zijlstra
2012-06-05 19:49 ` Peter Zijlstra
2012-06-05 19:51 ` Arjan van de Ven
2012-06-05 19:52 ` Peter Zijlstra
2012-06-05 20:47 ` Thomas Gleixner
2012-06-05 21:30 ` Peter Zijlstra
2012-06-05 22:09 ` Thomas Gleixner
2012-06-06 8:23 ` Peter Zijlstra
2012-06-06 8:30 ` Peter Zijlstra
2012-06-06 8:40 ` Peter Zijlstra
2012-06-05 22:12 ` Paul E. McKenney
2012-06-06 8:40 ` Peter Zijlstra
2012-06-06 8:42 ` Peter Zijlstra [this message]
2012-06-06 14:44 ` Paul E. McKenney
2012-06-06 15:46 ` Peter Zijlstra
2012-06-06 23:20 ` Paul E. McKenney
2012-06-08 9:20 ` Peter Zijlstra
2012-06-06 8:43 ` Peter Zijlstra
2012-06-06 14:41 ` Paul E. McKenney
2012-06-06 15:23 ` Arjan van de Ven
2012-06-06 15:48 ` Peter Zijlstra
2012-06-06 15:49 ` Paul E. McKenney
2012-06-06 16:59 ` Arjan van de Ven
2012-06-05 21:29 ` Paul E. McKenney
2012-06-05 21:37 ` Peter Zijlstra
2012-06-05 22:00 ` Paul E. McKenney
2012-06-06 12:17 ` Peter Zijlstra
2012-06-06 14:43 ` Paul E. McKenney
2012-06-05 19:51 ` Peter Zijlstra
2012-06-05 20:58 ` Andi Kleen
2012-06-05 21:15 ` Thomas Gleixner
2012-06-05 21:33 ` Thomas Gleixner
2012-06-05 23:13 ` Andi Kleen
2012-06-06 1:52 ` Arjan van de Ven
2012-06-05 18:07 ` Peter Zijlstra
2012-06-05 19:54 ` Luck, Tony
2012-06-05 19:56 ` Peter Zijlstra
2012-06-05 9:36 ` Thomas Gleixner
2012-06-05 13:41 ` [PATCH] kthread: Implement park/unpark facility Thomas Gleixner
2012-06-05 14:01 ` Peter Zijlstra
2012-06-05 14:05 ` Peter Zijlstra
2012-06-07 0:04 ` H. Peter Anvin
2012-06-10 5:40 ` Rusty Russell
2012-06-11 9:26 ` Thomas Gleixner
2012-06-12 0:23 ` Rusty Russell
2012-06-05 15:35 ` [PATCH 0/6] x86/cpu hotplug: Wake up offline CPU via mwait or nmi Jiang Liu
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