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Commit 1230db8e authored by Huang Ying's avatar Huang Ying Committed by Ingo Molnar
Browse files

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: default avatarHuang Ying <ying.huang@intel.com>
Acked-by: default avatarMathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: default avatarPeter 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: default avatarIngo Molnar <mingo@elte.hu>
parent 22f92bac
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+0 −1
Original line number Diff line number Diff line
@@ -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
+58 −6
Original line number Diff line number Diff line
@@ -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 */
+0 −3
Original line number Diff line number Diff line
@@ -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
+1 −3
Original line number Diff line number Diff line
@@ -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

+0 −40
Original line number Diff line number Diff line
@@ -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);