From 5aa2da2b35d7a0683e9ed0626b93ed35cc6ed6c1 Mon Sep 17 00:00:00 2001 From: Huang Ying Date: Wed, 28 Sep 2011 10:50:47 +1000 Subject: [PATCH] llist: make all llist functions inline Because llist may be used in performance critical code path, make all llist functions inline to avoid function calling overhead. Signed-off-by: Huang Ying Acked-by: Mathieu Desnoyers Cc: Peter Zijlstra Cc: Andi Kleen Signed-off-by: Andrew Morton <> --- drivers/acpi/apei/Kconfig | 1 - include/linux/llist.h | 122 +++++++++++++++++++++++++++++++++-- lib/Kconfig | 3 - lib/Makefile | 2 - lib/llist.c | 129 -------------------------------------- 5 files changed, 116 insertions(+), 141 deletions(-) delete mode 100644 lib/llist.c diff --git a/drivers/acpi/apei/Kconfig b/drivers/acpi/apei/Kconfig index e3f47872ec22..f0c1ce95a0ec 100644 --- a/drivers/acpi/apei/Kconfig +++ b/drivers/acpi/apei/Kconfig @@ -14,7 +14,6 @@ config ACPI_APEI_GHES depends on ACPI_APEI && X86 select ACPI_HED select IRQ_WORK - select LLIST select GENERIC_ALLOCATOR help Generic Hardware Error Source provides a way to report diff --git a/include/linux/llist.h b/include/linux/llist.h index aa0c8b5b3cd0..9be482e024de 100644 --- a/include/linux/llist.h +++ b/include/linux/llist.h @@ -37,8 +37,28 @@ * architectures that don't have NMI-safe cmpxchg implementation, the * list can NOT be used in NMI handler. So code uses the list in NMI * handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. + * + * Copyright 2010,2011 Intel Corp. + * Author: Huang Ying + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version + * 2 as published by the Free Software Foundation; + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include +#include +#include + struct llist_head { struct llist_node *first; }; @@ -113,14 +133,104 @@ static inline void init_llist_head(struct llist_head *list) * test whether the list is empty without deleting something from the * list. */ -static inline int llist_empty(const struct llist_head *head) +static inline bool llist_empty(const struct llist_head *head) { return ACCESS_ONCE(head->first) == NULL; } -void llist_add(struct llist_node *new, struct llist_head *head); -void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, - struct llist_head *head); -struct llist_node *llist_del_first(struct llist_head *head); -struct llist_node *llist_del_all(struct llist_head *head); +/** + * llist_add - add a new entry + * @new: new entry to be added + * @head: the head for your lock-less list + */ +static inline void llist_add(struct llist_node *new, struct llist_head *head) +{ + struct llist_node *entry, *old_entry; + +#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + BUG_ON(in_nmi()); +#endif + + entry = head->first; + do { + old_entry = entry; + new->next = entry; + cpu_relax(); + } while ((entry = cmpxchg(&head->first, old_entry, new)) != old_entry); +} + +/** + * llist_add_batch - add several linked entries in batch + * @new_first: first entry in batch to be added + * @new_last: last entry in batch to be added + * @head: the head for your lock-less list + */ +static inline void llist_add_batch(struct llist_node *new_first, + struct llist_node *new_last, + struct llist_head *head) +{ + struct llist_node *entry, *old_entry; + +#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + BUG_ON(in_nmi()); +#endif + + entry = head->first; + do { + old_entry = entry; + new_last->next = entry; + cpu_relax(); + } while ((entry = cmpxchg(&head->first, old_entry, new_first)) != old_entry); +} + +/** + * llist_del_first - delete the first entry of lock-less list + * @head: the head for your lock-less list + * + * If list is empty, return NULL, otherwise, return the first entry + * deleted, this is the newest added one. + * + * Only one llist_del_first user can be used simultaneously with + * multiple llist_add users without lock. Because otherwise + * llist_del_first, llist_add, llist_add (or llist_del_all, llist_add, + * llist_add) sequence in another user may change @head->first->next, + * but keep @head->first. If multiple consumers are needed, please + * use llist_del_all or use lock between consumers. + */ +static inline struct llist_node *llist_del_first(struct llist_head *head) +{ + struct llist_node *entry, *old_entry, *next; + +#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + BUG_ON(in_nmi()); +#endif + + entry = head->first; + do { + if (entry == NULL) + return NULL; + old_entry = entry; + next = entry->next; + cpu_relax(); + } while ((entry = cmpxchg(&head->first, old_entry, next)) != old_entry); + + return entry; +} + +/** + * llist_del_all - delete all entries from lock-less list + * @head: the head of lock-less list to delete all entries + * + * If list is empty, return NULL, otherwise, delete all entries and + * return the pointer to the first entry. The order of entries + * deleted is from the newest to the oldest added one. + */ +static inline struct llist_node *llist_del_all(struct llist_head *head) +{ +#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + BUG_ON(in_nmi()); +#endif + + return xchg(&head->first, NULL); +} #endif /* LLIST_H */ diff --git a/lib/Kconfig b/lib/Kconfig index 6c695ff9caba..32f3e5ae2be5 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -276,7 +276,4 @@ config CORDIC so its calculations are in fixed point. Modules can select this when they require this function. Module will be called cordic. -config LLIST - bool - endmenu diff --git a/lib/Makefile b/lib/Makefile index 7d500a5f283f..b22119041109 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -116,8 +116,6 @@ obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o obj-$(CONFIG_CORDIC) += cordic.o -obj-$(CONFIG_LLIST) += llist.o - hostprogs-y := gen_crc32table clean-files := crc32table.h diff --git a/lib/llist.c b/lib/llist.c deleted file mode 100644 index da445724fa1f..000000000000 --- a/lib/llist.c +++ /dev/null @@ -1,129 +0,0 @@ -/* - * Lock-less NULL terminated single linked list - * - * The basic atomic operation of this list is cmpxchg on long. On - * architectures that don't have NMI-safe cmpxchg implementation, the - * list can NOT be used in NMI handler. So code uses the list in NMI - * handler should depend on CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG. - * - * Copyright 2010,2011 Intel Corp. - * Author: Huang Ying - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public License version - * 2 as published by the Free Software Foundation; - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -#include -#include -#include -#include - -#include - -/** - * llist_add - add a new entry - * @new: new entry to be added - * @head: the head for your lock-less list - */ -void llist_add(struct llist_node *new, struct llist_head *head) -{ - struct llist_node *entry, *old_entry; - -#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - BUG_ON(in_nmi()); -#endif - - entry = head->first; - do { - old_entry = entry; - new->next = entry; - cpu_relax(); - } while ((entry = cmpxchg(&head->first, old_entry, new)) != old_entry); -} -EXPORT_SYMBOL_GPL(llist_add); - -/** - * llist_add_batch - add several linked entries in batch - * @new_first: first entry in batch to be added - * @new_last: last entry in batch to be added - * @head: the head for your lock-less list - */ -void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, - struct llist_head *head) -{ - struct llist_node *entry, *old_entry; - -#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - BUG_ON(in_nmi()); -#endif - - entry = head->first; - do { - old_entry = entry; - new_last->next = entry; - cpu_relax(); - } while ((entry = cmpxchg(&head->first, old_entry, new_first)) != old_entry); -} -EXPORT_SYMBOL_GPL(llist_add_batch); - -/** - * llist_del_first - delete the first entry of lock-less list - * @head: the head for your lock-less list - * - * If list is empty, return NULL, otherwise, return the first entry - * deleted, this is the newest added one. - * - * Only one llist_del_first user can be used simultaneously with - * multiple llist_add users without lock. Because otherwise - * llist_del_first, llist_add, llist_add (or llist_del_all, llist_add, - * llist_add) sequence in another user may change @head->first->next, - * but keep @head->first. If multiple consumers are needed, please - * use llist_del_all or use lock between consumers. - */ -struct llist_node *llist_del_first(struct llist_head *head) -{ - struct llist_node *entry, *old_entry, *next; - -#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - BUG_ON(in_nmi()); -#endif - - entry = head->first; - do { - if (entry == NULL) - return NULL; - old_entry = entry; - next = entry->next; - cpu_relax(); - } while ((entry = cmpxchg(&head->first, old_entry, next)) != old_entry); - - return entry; -} -EXPORT_SYMBOL_GPL(llist_del_first); - -/** - * llist_del_all - delete all entries from lock-less list - * @head: the head of lock-less list to delete all entries - * - * If list is empty, return NULL, otherwise, delete all entries and - * return the pointer to the first entry. The order of entries - * deleted is from the newest to the oldest added one. - */ -struct llist_node *llist_del_all(struct llist_head *head) -{ -#ifndef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - BUG_ON(in_nmi()); -#endif - - return xchg(&head->first, NULL); -} -EXPORT_SYMBOL_GPL(llist_del_all); -- 2.39.5