Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755407Ab0AEWtJ (ORCPT ); Tue, 5 Jan 2010 17:49:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754921Ab0AEWtH (ORCPT ); Tue, 5 Jan 2010 17:49:07 -0500 Received: from tomts20-srv.bellnexxia.net ([209.226.175.74]:43665 "EHLO tomts20-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754591Ab0AEWtG (ORCPT ); Tue, 5 Jan 2010 17:49:06 -0500 Date: Tue, 5 Jan 2010 17:49:01 -0500 From: Mathieu Desnoyers To: Christoph Lameter Cc: Tejun Heo , linux-kernel@vger.kernel.org Subject: Re: [RFC local_t removal V1 1/4] Add add_local() and add_local_return() Message-ID: <20100105224901.GB32584@Krystal> References: <20100105220417.400092933@quilx.com> <20100105220437.940473705@quilx.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20100105220437.940473705@quilx.com> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.27.31-grsec (i686) X-Uptime: 17:46:04 up 20 days, 7:04, 5 users, load average: 0.19, 0.49, 0.32 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 11548 Lines: 277 * 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 > > --- > 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 > + > +#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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > 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 > + > +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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/