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llist: Make some llist functions inline 

Because llist code will be used in performance critical scheduler
code path, make llist_add() and llist_del_all() inline to avoid
function calling overhead and related 'glue' overhead.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1315461646-1379-2-git-send-email-ying.huang@intel.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Huang Ying 2011-09-08 14:00:42 +08:00 committed by Ingo Molnar
parent 22f92bacbe
commit 1230db8e15
5 changed files with 59 additions and 53 deletions
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1
drivers/acpi/apei/Kconfig
View File

@ -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

64
include/linux/llist.h
View File

@ -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 <ying.huang@intel.com>
*
* 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 <linux/kernel.h>
#include <asm/system.h>
#include <asm/processor.h>
struct llist_head {
struct llist_node *first;
};
@ -113,14 +133,46 @@ 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_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 */

3
lib/Kconfig
View File

@ -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

4
lib/Makefile
View File

@ -22,7 +22,7 @@ lib-y += kobject.o kref.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 \
string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o \
bsearch.o find_last_bit.o find_next_bit.o
bsearch.o find_last_bit.o find_next_bit.o llist.o
obj-y += kstrtox.o
obj-$(CONFIG_TEST_KSTRTOX) += test-kstrtox.o
@ -115,8 +115,6 @@ obj-$(CONFIG_CPU_RMAP) += cpu_rmap.o
obj-$(CONFIG_CORDIC) += cordic.o
obj-$(CONFIG_LLIST) += llist.o
hostprogs-y := gen_crc32table
clean-files := crc32table.h

40
lib/llist.c
View File

@ -29,28 +29,6 @@
#include <asm/system.h>
/**
* 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
@ -109,21 +87,3 @@ struct llist_node *llist_del_first(struct llist_head *head)
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);