From: Mathieu Desnoyers <compudj@krystal.dyndns.org>
To: David Miller <davem@davemloft.net>
Cc: ltt-dev@lists.casi.polymtl.ca, mingo@elte.hu,
paulmck@linux.vnet.ibm.com, jwboyer@linux.vnet.ibm.com,
linux-kernel@vger.kernel.org
Subject: Re: cli/sti vs local_cmpxchg and local_add_return
Date: Tue, 17 Mar 2009 15:35:32 -0400 [thread overview]
Message-ID: <20090317193532.GA18503@Krystal> (raw)
In-Reply-To: <20090317.122816.246078801.davem@davemloft.net>
* David Miller (davem@davemloft.net) wrote:
> From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
> Date: Tue, 17 Mar 2009 12:06:35 -0400
>
> > But powerpc has non-maskable interrupts, so for less than 4 cycles, I
> > think it's better to stay with the local_t variant to be NMI-safe.
>
> Sparc64 has non-maskable interrupts too btw.
>
OK, this alone is a strong argument to favor NMI-safe lockless algorithm
even if it is a bit slower. We should see what kind of performance
impact it has on overall tracing performance to find out if it will make
a measurable difference anyway.
Mathieu
> _______________________________________________
> ltt-dev mailing list
> ltt-dev@lists.casi.polymtl.ca
> http://lists.casi.polymtl.ca/cgi-bin/mailman/listinfo/ltt-dev
>
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
next prev parent reply other threads:[~2009-03-17 19:35 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-03-17 1:32 cli/sti vs local_cmpxchg and local_add_return Mathieu Desnoyers
2009-03-17 3:37 ` David Miller
2009-03-17 4:10 ` Mathieu Desnoyers
2009-03-17 4:27 ` David Miller
2009-03-17 4:44 ` Mathieu Desnoyers
2009-03-17 5:01 ` Paul E. McKenney
2009-03-17 16:06 ` Mathieu Desnoyers
2009-03-17 19:28 ` David Miller
2009-03-17 19:35 ` Mathieu Desnoyers [this message]
2009-03-17 6:05 ` Nick Piggin
2009-03-17 15:14 ` [ltt-dev] " Mathieu Desnoyers
2009-03-18 11:43 ` Nick Piggin
2009-03-18 15:10 ` Mathieu Desnoyers
2009-03-17 18:42 ` Alan D. Brunelle
2009-03-17 19:01 ` Andika Triwidada
2009-03-23 16:50 ` Mathieu Desnoyers
2009-03-18 11:56 ` Josh Boyer
2009-03-23 16:56 ` Mathieu Desnoyers
2009-03-23 17:04 ` Josh Boyer
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