From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Christoph Lameter <cl@linux.com>
Cc: akpm@linux-foundation.org, Pekka Enberg <penberg@cs.helsinki.fi>,
linux-kernel@vger.kernel.org,
Eric Dumazet <eric.dumazet@gmail.com>, Tejun Heo <tj@kernel.org>
Subject: Re: [thisops uV2 04/10] x86: Support for this_cpu_add,sub,dec,inc_return
Date: Mon, 29 Nov 2010 13:33:33 -0500 [thread overview]
Message-ID: <20101129183333.GA25610@Krystal> (raw)
In-Reply-To: <alpine.DEB.2.00.1011291025410.3923@router.home>
* Christoph Lameter (cl@linux.com) wrote:
> On Sat, 27 Nov 2010, Mathieu Desnoyers wrote:
>
> > > +/*
> > > + * Add return operation
> > > + */
> > > +#define percpu_add_return_op(var, val) \
> > > +({ \
> > > + typedef typeof(var) pao_T__; \
> > > + typeof(var) pfo_ret__ = val; \
> > > + if (0) { \
> > > + pao_T__ pao_tmp__; \
> > > + pao_tmp__ = (val); \
> > > + (void)pao_tmp__; \
> > > + } \
> >
> > OK, I'm dumb: why is the above needed ?
>
> Ensure that the compiler agrees that *var and val are compatible. Taken
> over from percpu_add_op().
Isn't that the purpose of __builtin_types_compatible_p(t1, t2) ?
Mathieu
--
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2010-11-29 18:33 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-26 21:09 [thisops uV2 00/10] Upgrade of this_cpu_ops V2 Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 01/10] percpucounter: Optimize __percpu_counter_add a bit through the use of this_cpu() options Christoph Lameter
2010-11-27 14:42 ` Mathieu Desnoyers
2010-11-26 21:09 ` [thisops uV2 02/10] vmstat: Optimize zone counter modifications through the use of this cpu operations Christoph Lameter
2010-11-27 8:00 ` Pekka Enberg
2010-11-27 14:49 ` Mathieu Desnoyers
2010-11-29 16:16 ` Christoph Lameter
2010-11-29 17:13 ` Christoph Lameter
2010-11-29 19:28 ` Mathieu Desnoyers
2010-11-29 20:07 ` Christoph Lameter
2010-11-29 20:59 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 03/10] percpu: Generic support for this_cpu_add,sub,dec,inc_return Christoph Lameter
2010-11-27 14:58 ` Mathieu Desnoyers
2010-11-29 16:08 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 04/10] x86: Support " Christoph Lameter
2010-11-27 8:06 ` Pekka Enberg
2010-11-29 16:03 ` Christoph Lameter
2010-11-27 15:00 ` Mathieu Desnoyers
2010-11-29 16:31 ` Christoph Lameter
2010-11-29 18:33 ` Mathieu Desnoyers [this message]
2010-11-29 18:54 ` Christoph Lameter
2010-11-29 19:22 ` Mathieu Desnoyers
2010-11-29 20:09 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 05/10] x86: Use this_cpu_inc_return for nmi counter Christoph Lameter
2010-11-27 8:07 ` Pekka Enberg
2010-11-27 15:00 ` Mathieu Desnoyers
2010-11-26 21:09 ` [thisops uV2 06/10] vmstat: Use this_cpu_inc_return for vm statistics Christoph Lameter
2010-11-27 8:09 ` Pekka Enberg
2010-11-29 16:04 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 07/10] highmem: Use this_cpu_xx_return() operations Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 08/10] percpu: generic this_cpu_cmpxchg() and this_cpu_cmpxchg_double support Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 09/10] x86: this_cpu_cmpxchg and this_cpu_cmpxchg_double operations Christoph Lameter
2010-11-27 6:30 ` Eric Dumazet
2010-11-27 15:20 ` Mathieu Desnoyers
2010-11-29 16:11 ` Christoph Lameter
2010-11-26 21:09 ` [thisops uV2 10/10] slub: Lockless fastpaths Christoph Lameter
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