[patch] uninline init_waitqueue_head()

Ingo Molnar
2006-07-06T09:17:23Z

* Andrew Morton <akpm@osdl.org> wrote:

> On my x86_64 typicalconfig
> (http://www.zip.com.au/~akpm/linux/patches/stuff/config-x)
>
> everything inlined:
>
> text data bss dec hex filename
> 4079169 702440 280184 5061793 4d3ca1 vmlinux
>
> uninline init_waitqueue_head:
>
> 4076921 702456 280184 5059561 4d33e9 vmlinux
>
> uninline init_waitqueue_head+init_waitqueue_entry
>
> box:/usr/src/25> size vmlinux
> text data bss dec hex filename
> 4077017 702472 280184 5059673 4d3459 vmlinux
>
> uninline init_waitqueue_head+init_waitqueue_entry+init_waitqueue_func_entry
>
> box:/usr/src/25> size vmlinux
> text data bss dec hex filename
> 4077128 702496 280184 5059808 4d34e0 vmlinux
>
> So we only want to uninline init_waitqueue_head().

yeah, i played with that too and concluded that it's a small win on i386
:-) Anyway, updated patch below - i agree that the biggest item is
init_waitqueue_head().

Ingo

---------------->
Subject: uninline init_waitqueue_head()
From: Ingo Molnar <mingo@elte.hu>

uninline more wait.h inline functions.

allyesconfig vmlinux size delta:

text data bss dec filename
20736884 6073834 3075176 29885894 vmlinux.before
20721009 6073966 3075176 29870151 vmlinux.after

~18 bytes per callsite, 15K of text size (~0.1%) saved.

(as an added bonus this also removes a lockdep annotation.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
---
include/linux/wait.h | 12 +-----------
kernel/wait.c | 8 ++++++--
2 files changed, 7 insertions(+), 13 deletions(-)

Index: linux/include/linux/wait.h
===================================================================
--- linux.orig/include/linux/wait.h
+++ linux/include/linux/wait.h
@@ -77,17 +77,7 @@ struct task_struct;
#define __WAIT_BIT_KEY_INITIALIZER(word, bit) \
{ .flags = word, .bit_nr = bit, }

-/*
- * lockdep: we want one lock-class for all waitqueue locks.
- */
-extern struct lock_class_key waitqueue_lock_key;
-
-static inline void init_waitqueue_head(wait_queue_head_t *q)
-{
- spin_lock_init(&q->lock);
- lockdep_set_class(&q->lock, &waitqueue_lock_key);
- INIT_LIST_HEAD(&q->task_list);
-}
+extern void init_waitqueue_head(wait_queue_head_t *q);

static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
{
Index: linux/kernel/wait.c
===================================================================
--- linux.orig/kernel/wait.c
+++ linux/kernel/wait.c
@@ -10,9 +10,13 @@
#include <linux/wait.h>
#include <linux/hash.h>

-struct lock_class_key waitqueue_lock_key;
+void init_waitqueue_head(wait_queue_head_t *q)
+{
+ spin_lock_init(&q->lock);
+ INIT_LIST_HEAD(&q->task_list);
+}

-EXPORT_SYMBOL(waitqueue_lock_key);
+EXPORT_SYMBOL(init_waitqueue_head);

void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
{