From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Peter Zijlstra <peterz@infradead.org>,
Milton Miller <miltonm@bga.com>,
akpm@linux-foundation.org, Anton Blanchard <anton@samba.org>,
xiaoguangrong@cn.fujitsu.com, mingo@elte.hu, jaxboe@fusionio.com,
npiggin@gmail.com, rusty@rustcorp.com.au,
linux-kernel@vger.kernel.org
Subject: Re: call_function_many: fix list delete vs add race
Date: Tue, 1 Feb 2011 06:13:01 -0800 [thread overview]
Message-ID: <20110201141301.GA23646@linux.vnet.ibm.com> (raw)
In-Reply-To: <AANLkTikZXh4NbwTCj22dTAEjnNjtEdGtQpTDChw=fckN@mail.gmail.com>
On Tue, Feb 01, 2011 at 03:46:26PM +1000, Linus Torvalds wrote:
> On Tue, Feb 1, 2011 at 2:45 PM, Paul E. McKenney
> <paulmck@linux.vnet.ibm.com> wrote:
> > On Tue, Feb 01, 2011 at 12:43:56PM +1000, Linus Torvalds wrote:
> >>
> >> That said, I do think that if your memory ordering is much weaker than
> >> x86, you are going to see bugs that most testers don't see, and it
> >> simply might not be worth it.
> >
> > IBM's CPUs do split the difference, with s390 having somewhat stronger
> > ordering than x86, and with powerpc being rather weaker
>
> I'm not talking about memory ordering as done by the cpu, but as done
> by the spinlock operations. They can be arbitrarily strong, even if
> the CPU architecture itself might be weakly ordered.
Got it.
[ . . . ]
> Quite frankly, the POWER case is made worse by the fact that the
> synchronization primitives have this total confusion about "pipeline"
> synchronization due to historical implementation oddities etc. Talk
> about crazy. The whole "isync" vs "sync" vs "lwsync" thing is just an
> embarrassment.
I am always ready to exploit embarrassing parallelism!
Thanx, Paul
next prev parent reply other threads:[~2011-02-01 14:13 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-12 4:07 [PATCH] smp_call_function_many SMP race Anton Blanchard
2011-01-17 18:17 ` Peter Zijlstra
2011-01-18 21:05 ` Milton Miller
2011-01-18 21:06 ` [PATCH 2/2] consolidate writes in smp_call_funtion_interrupt Milton Miller
2011-01-27 16:22 ` Peter Zijlstra
2011-01-27 21:59 ` Milton Miller
2011-01-29 0:20 ` call_function_many: fix list delete vs add race Milton Miller
2011-01-31 7:21 ` Mike Galbraith
2011-01-31 20:26 ` [PATCH] smp_call_function_many: handle concurrent clearing of mask Milton Miller
2011-02-01 3:15 ` Mike Galbraith
2011-01-31 10:27 ` call_function_many: fix list delete vs add race Peter Zijlstra
2011-01-31 20:26 ` Milton Miller
2011-01-31 20:39 ` Peter Zijlstra
2011-01-31 21:17 ` Peter Zijlstra
2011-01-31 21:36 ` Milton Miller
2011-02-01 0:22 ` Benjamin Herrenschmidt
2011-02-01 1:39 ` Linus Torvalds
2011-02-01 2:18 ` Paul E. McKenney
2011-02-01 2:43 ` Linus Torvalds
2011-02-01 4:45 ` Paul E. McKenney
2011-02-01 5:46 ` Linus Torvalds
2011-02-01 6:18 ` Benjamin Herrenschmidt
2011-02-01 14:13 ` Paul E. McKenney [this message]
2011-02-01 6:16 ` Benjamin Herrenschmidt
[not found] ` <ipi-list-reply@mdm.bga.com>
2011-02-01 7:12 ` [PATCH 1/3 v2] " Milton Miller
2011-02-01 22:00 ` Paul E. McKenney
2011-02-01 22:00 ` Milton Miller
2011-02-02 4:17 ` Paul E. McKenney
2011-02-06 23:51 ` Paul E. McKenney
2011-03-15 19:27 ` [PATCH 0/4 v3] smp_call_function_many issues from review Milton Miller
2011-03-15 20:22 ` Luck, Tony
2011-03-15 20:32 ` Dimitri Sivanich
2011-03-15 20:39 ` Peter Zijlstra
2011-03-16 17:55 ` Linus Torvalds
2011-03-16 18:13 ` Peter Zijlstra
2011-03-17 3:15 ` Mike Galbraith
2011-02-07 8:12 ` [PATCH 1/3 v2] call_function_many: fix list delete vs add race Mike Galbraith
2011-02-08 19:36 ` Paul E. McKenney
2011-08-21 6:17 ` Mike Galbraith
2011-02-02 6:22 ` Mike Galbraith
2011-02-01 7:12 ` [PATCH 2/3 v2] smp_call_function_many: handle concurrent clearing of mask Milton Miller
2011-03-15 19:27 ` [PATCH 2/4 v3] call_function_many: add missing ordering Milton Miller
2011-03-16 12:06 ` Paul E. McKenney
2011-03-15 19:27 ` [PATCH 1/4 v3] call_function_many: fix list delete vs add race Milton Miller
2011-03-15 19:27 ` [PATCH 4/4 v3] smp_call_function_interrupt: use typedef and %pf Milton Miller
2011-03-15 19:27 ` [PATCH 3/4 v3] smp_call_function_many: handle concurrent clearing of mask Milton Miller
2011-03-15 22:32 ` Catalin Marinas
2011-03-16 7:52 ` Jan Beulich
2011-01-18 21:07 ` [PATCH 1/2] smp_call_function_many SMP race Milton Miller
2011-01-20 0:41 ` Andrew Morton
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