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From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
To: Christoph Lameter <cl@linux-foundation.org>
Cc: Tejun Heo <tj@kernel.org>, linux-kernel@vger.kernel.org
Subject: Re: [RFC local_t removal V1 1/4] Add add_local() and add_local_return()
Date: Tue, 5 Jan 2010 17:49:01 -0500	[thread overview]
Message-ID: <20100105224901.GB32584@Krystal> (raw)
In-Reply-To: <20100105220437.940473705@quilx.com>

* Christoph Lameter (cl@linux-foundation.org) wrote:
> We already have cmpxchg_local that can work on an arbitrary type. The cmpxchg
> is only safe from concurrent access on the local cpu.
> 
> Add another operation that in the similar fasion allow "local" safe adds to
> a variable.
> 
> Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
> 
> ---
>  arch/alpha/include/asm/add-local.h      |    2 +
>  arch/arm/include/asm/add-local.h        |    2 +
>  arch/avr32/include/asm/add-local.h      |    2 +
>  arch/blackfin/include/asm/add-local.h   |    2 +
>  arch/cris/include/asm/add-local.h       |    2 +
>  arch/frv/include/asm/add-local.h        |    2 +
>  arch/h8300/include/asm/add-local.h      |    2 +
>  arch/ia64/include/asm/add-local.h       |    2 +
>  arch/m32r/include/asm/add-local.h       |    2 +
>  arch/m68k/include/asm/add-local.h       |    2 +
>  arch/microblaze/include/asm/add-local.h |    2 +
>  arch/mips/include/asm/add-local.h       |    2 +
>  arch/mn10300/include/asm/add-local.h    |    2 +
>  arch/parisc/include/asm/add-local.h     |    2 +
>  arch/powerpc/include/asm/add-local.h    |    2 +
>  arch/s390/include/asm/add-local.h       |    2 +
>  arch/score/include/asm/add-local.h      |    2 +
>  arch/sh/include/asm/add-local.h         |    2 +
>  arch/sparc/include/asm/add-local.h      |    2 +
>  arch/um/include/asm/add-local.h         |    2 +
>  arch/x86/include/asm/add-local.h        |    2 +
>  arch/xtensa/include/asm/add-local.h     |    2 +
>  include/asm-generic/add-local-generic.h |   40 ++++++++++++++++++++++++++++++++
>  include/asm-generic/add-local.h         |   13 ++++++++++
>  24 files changed, 97 insertions(+)

The problem I see here is that with ~5-6 operations, we will end up
having 20*5 = 100 headers only for this. Can we combine these in a
single header file instead ? local.h wasn't bad in this respect.

Also, separating all these in sub-files will make it a bit difficult to
pinpoint errors that would arise from using a bad combination of, e.g.
generic add with a non-protected read or set.

Thanks,

Mathieu

> 
> Index: linux-2.6/include/asm-generic/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/include/asm-generic/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,13 @@
> +#ifndef __ASM_GENERIC_ADD_LOCAL_H
> +#define __ASM_GENERIC_ADD_LOCAL_H
> +
> +#include <asm-generic/add-local-generic.h>
> +
> +#define add_return_local(ptr, v)				  	\
> +	((__typeof__(*(ptr)))__add_return_local_generic((ptr), 		\
> +			(unsigned long)(v), sizeof(*(ptr))))
> +
> +#define add_local(ptr, v) (void)__add_return_local_generic((ptr),	\
> +			(unsigned long)(v), sizeof(*(ptr)))
> +
> +#endif
> Index: linux-2.6/arch/alpha/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/alpha/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/arm/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/arm/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/avr32/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/avr32/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/blackfin/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/blackfin/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/cris/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/cris/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/frv/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/frv/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/h8300/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/h8300/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/ia64/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/ia64/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/m32r/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/m32r/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/m68k/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/m68k/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/microblaze/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/microblaze/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/mips/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/mips/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/mn10300/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/mn10300/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/parisc/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/parisc/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/powerpc/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/powerpc/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/s390/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/s390/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/score/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/score/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/sh/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/sh/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/sparc/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/sparc/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/um/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/um/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/x86/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/x86/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/arch/xtensa/include/asm/add-local.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/arch/xtensa/include/asm/add-local.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,2 @@
> +#include <asm-generic/add-local.h>
> +
> Index: linux-2.6/include/asm-generic/add-local-generic.h
> ===================================================================
> --- /dev/null	1970-01-01 00:00:00.000000000 +0000
> +++ linux-2.6/include/asm-generic/add-local-generic.h	2010-01-05 15:36:02.000000000 -0600
> @@ -0,0 +1,40 @@
> +#ifndef __ASM_GENERIC_ADD_LOCAL_GENERIC_H
> +#define __ASM_GENERIC_ADD_LOCAL_GENERIC_H
> +
> +#include <linux/types.h>
> +
> +extern unsigned long wrong_size_add_local(volatile void *ptr);
> +
> +/*
> + * Generic version of __add_return_local (disables interrupts). Takes an
> + * unsigned long parameter, supporting various types of architectures.
> + */
> +static inline unsigned long __add_return_local_generic(volatile void *ptr,
> +		unsigned long value, int size)
> +{
> +	unsigned long flags, r;
> +
> +	/*
> +	 * Sanity checking, compile-time.
> +	 */
> +	if (size == 8 && sizeof(unsigned long) != 8)
> +		wrong_size_add_local(ptr);
> +
> +	local_irq_save(flags);
> +	switch (size) {
> +	case 1: r = (*((u8 *)ptr) += value);
> +		break;
> +	case 2: r = (*((u16 *)ptr) += value);
> +		break;
> +	case 4: r = (*((u32 *)ptr) += value);
> +		break;
> +	case 8: r = (*((u64 *)ptr) += value);
> +		break;
> +	default:
> +		wrong_size_add_local(ptr);
> +	}
> +	local_irq_restore(flags);
> +	return r;
> +}
> +
> +#endif
> 
> -- 

-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68

  parent reply	other threads:[~2010-01-05 22:49 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-01-05 22:04 [RFC local_t removal V1 0/4] Remove local_t Christoph Lameter
2010-01-05 22:04 ` [RFC local_t removal V1 1/4] Add add_local() and add_local_return() Christoph Lameter
2010-01-05 22:17   ` Mike Frysinger
2010-01-05 22:29     ` Christoph Lameter
2010-01-06 19:23       ` Mike Frysinger
2010-01-07 17:03         ` Christoph Lameter
2010-01-05 22:49   ` Mathieu Desnoyers [this message]
2010-01-07 13:45     ` Arnd Bergmann
2010-01-07 13:57       ` Mathieu Desnoyers
2010-01-07 14:22         ` Arnd Bergmann
2010-01-07 17:07     ` Christoph Lameter
2010-01-05 22:04 ` [RFC local_t removal V1 2/4] Replace local_t use in trace subsystem Christoph Lameter
2010-01-05 22:57   ` Mathieu Desnoyers
2010-01-07 17:15     ` Christoph Lameter
2010-01-14  2:56   ` Steven Rostedt
2010-01-14 14:49     ` Christoph Lameter
2010-01-05 22:04 ` [RFC local_t removal V1 3/4] Optimized add_local() Christoph Lameter
2010-01-05 22:59   ` Mathieu Desnoyers
2010-01-07 17:16     ` Christoph Lameter
2010-01-05 22:04 ` [RFC local_t removal V1 4/4] Remove local_t support Christoph Lameter
2010-01-05 22:23 ` [RFC local_t removal V1 0/4] Remove local_t Mathieu Desnoyers
2010-01-05 22:34   ` Christoph Lameter
2010-01-05 22:45     ` Mathieu Desnoyers
2010-01-07 17:05       ` Christoph Lameter

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