From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753161Ab1LMJhU (ORCPT ); Tue, 13 Dec 2011 04:37:20 -0500 Received: from casper.infradead.org ([85.118.1.10]:60370 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750820Ab1LMJhP convert rfc822-to-8bit (ORCPT ); Tue, 13 Dec 2011 04:37:15 -0500 Message-ID: <1323768980.9082.6.camel@twins> Subject: Re: [PATCH 1/3] kref: Inline all functions From: Peter Zijlstra To: Greg KH Cc: gregkh@suse.de, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, ostrikov@nvidia.com, adobriyan@gmail.com, eric.dumazet@gmail.com, mingo@elte.hu Date: Tue, 13 Dec 2011 10:36:20 +0100 In-Reply-To: <20111212221159.GA27940@kroah.com> References: <20111210104341.592561407@chello.nl> <20111210104840.107647845@chello.nl> <20111212221159.GA27940@kroah.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT X-Mailer: Evolution 3.2.1- Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2011-12-12 at 14:11 -0800, Greg KH wrote: > Nice, but this breaks the build: Sorry about that, this one includes the missing include and just booted on my test-box. --- Subject: kref: Inline all functions From: Peter Zijlstra Date: Sat Dec 10 11:29:57 CET 2011 These are tiny functions, there's no point in having them out-of-line. Cc: adobriyan@gmail.com Cc: eric.dumazet@gmail.com Cc: mingo@elte.hu Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/n/tip-8eccvi2ur2fzgi00xdjlbf5z@git.kernel.org --- include/linux/kref.h | 80 +++++++++++++++++++++++++++++++++++++++--- lib/Makefile | 2 - lib/kref.c | 97 --------------------------------------------------- 3 files changed, 76 insertions(+), 103 deletions(-) Index: linux-2.6/include/linux/kref.h =================================================================== --- linux-2.6.orig/include/linux/kref.h +++ linux-2.6/include/linux/kref.h @@ -16,15 +16,85 @@ #define _KREF_H_ #include +#include struct kref { atomic_t refcount; }; -void kref_init(struct kref *kref); -void kref_get(struct kref *kref); -int kref_put(struct kref *kref, void (*release) (struct kref *kref)); -int kref_sub(struct kref *kref, unsigned int count, - void (*release) (struct kref *kref)); +/** + * kref_init - initialize object. + * @kref: object in question. + */ +static inline void kref_init(struct kref *kref) +{ + atomic_set(&kref->refcount, 1); + smp_mb(); +} +/** + * kref_get - increment refcount for object. + * @kref: object. + */ +static inline void kref_get(struct kref *kref) +{ + WARN_ON(!atomic_read(&kref->refcount)); + atomic_inc(&kref->refcount); + smp_mb__after_atomic_inc(); +} + +/** + * kref_put - decrement refcount for object. + * @kref: object. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. + * + * Decrement the refcount, and if 0, call release(). + * Return 1 if the object was removed, otherwise return 0. Beware, if this + * function returns 0, you still can not count on the kref from remaining in + * memory. Only use the return value if you want to see if the kref is now + * gone, not present. + */ +static inline int kref_put(struct kref *kref, void (*release)(struct kref *kref)) +{ + WARN_ON(release == NULL); + WARN_ON(release == (void (*)(struct kref *))kfree); + + if (atomic_dec_and_test(&kref->refcount)) { + release(kref); + return 1; + } + return 0; +} + + +/** + * kref_sub - subtract a number of refcounts for object. + * @kref: object. + * @count: Number of recounts to subtract. + * @release: pointer to the function that will clean up the object when the + * last reference to the object is released. + * This pointer is required, and it is not acceptable to pass kfree + * in as this function. + * + * Subtract @count from the refcount, and if 0, call release(). + * Return 1 if the object was removed, otherwise return 0. Beware, if this + * function returns 0, you still can not count on the kref from remaining in + * memory. Only use the return value if you want to see if the kref is now + * gone, not present. + */ +static inline int kref_sub(struct kref *kref, unsigned int count, + void (*release)(struct kref *kref)) +{ + WARN_ON(release == NULL); + WARN_ON(release == (void (*)(struct kref *))kfree); + + if (atomic_sub_and_test((int) count, &kref->refcount)) { + release(kref); + return 1; + } + return 0; +} #endif /* _KREF_H_ */ Index: linux-2.6/lib/kref.c =================================================================== --- linux-2.6.orig/lib/kref.c +++ /dev/null @@ -1,97 +0,0 @@ -/* - * kref.c - library routines for handling generic reference counted objects - * - * Copyright (C) 2004 Greg Kroah-Hartman - * Copyright (C) 2004 IBM Corp. - * - * based on lib/kobject.c which was: - * Copyright (C) 2002-2003 Patrick Mochel - * - * This file is released under the GPLv2. - * - */ - -#include -#include -#include - -/** - * kref_init - initialize object. - * @kref: object in question. - */ -void kref_init(struct kref *kref) -{ - atomic_set(&kref->refcount, 1); - smp_mb(); -} - -/** - * kref_get - increment refcount for object. - * @kref: object. - */ -void kref_get(struct kref *kref) -{ - WARN_ON(!atomic_read(&kref->refcount)); - atomic_inc(&kref->refcount); - smp_mb__after_atomic_inc(); -} - -/** - * kref_put - decrement refcount for object. - * @kref: object. - * @release: pointer to the function that will clean up the object when the - * last reference to the object is released. - * This pointer is required, and it is not acceptable to pass kfree - * in as this function. - * - * Decrement the refcount, and if 0, call release(). - * Return 1 if the object was removed, otherwise return 0. Beware, if this - * function returns 0, you still can not count on the kref from remaining in - * memory. Only use the return value if you want to see if the kref is now - * gone, not present. - */ -int kref_put(struct kref *kref, void (*release)(struct kref *kref)) -{ - WARN_ON(release == NULL); - WARN_ON(release == (void (*)(struct kref *))kfree); - - if (atomic_dec_and_test(&kref->refcount)) { - release(kref); - return 1; - } - return 0; -} - - -/** - * kref_sub - subtract a number of refcounts for object. - * @kref: object. - * @count: Number of recounts to subtract. - * @release: pointer to the function that will clean up the object when the - * last reference to the object is released. - * This pointer is required, and it is not acceptable to pass kfree - * in as this function. - * - * Subtract @count from the refcount, and if 0, call release(). - * Return 1 if the object was removed, otherwise return 0. Beware, if this - * function returns 0, you still can not count on the kref from remaining in - * memory. Only use the return value if you want to see if the kref is now - * gone, not present. - */ -int kref_sub(struct kref *kref, unsigned int count, - void (*release)(struct kref *kref)) -{ - WARN_ON(release == NULL); - WARN_ON(release == (void (*)(struct kref *))kfree); - - if (atomic_sub_and_test((int) count, &kref->refcount)) { - release(kref); - return 1; - } - return 0; -} - -EXPORT_SYMBOL(kref_init); -EXPORT_SYMBOL(kref_get); -EXPORT_SYMBOL(kref_put); -EXPORT_SYMBOL(kref_sub); Index: linux-2.6/lib/Makefile =================================================================== --- linux-2.6.orig/lib/Makefile +++ linux-2.6/lib/Makefile @@ -17,7 +17,7 @@ lib-y := ctype.o string.o vsprintf.o cmd lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o -lib-y += kobject.o kref.o klist.o +lib-y += kobject.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \