[2/2] reduce number of parameters to __wait_on_bit() and __wait_on_bit_lock()
From: William Lee Irwin III (wli_at_holomorphy.com)
Date: 08/31/04
- Previous message: Lee Revell: "Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q5"
- Next in thread: William Lee Irwin III: "[3/2] document wake_up_bit()'s requirement for preceding memory barriers"
- Reply: William Lee Irwin III: "[3/2] document wake_up_bit()'s requirement for preceding memory barriers"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Date: Tue, 31 Aug 2004 14:05:42 -0700 To: Andrew Morton <akpm@osdl.org>
On Tue, Aug 31, 2004 at 02:03:46PM -0700, William Lee Irwin III wrote:
> Move the slow paths of wait_on_bit() and wait_on_bit_lock() out of line.
> Also uninline wake_up_bit() to reduce the number of callsites
> generated, and adjust loop startup in __wait_on_bit_lock() to properly
> reflect its usage in the contention case.
> Incremental atop the fastcall and wait_on_bit_lock()/test_and_set_bit() fixes.
> Successfully tested on x86-64.
Some of the parameters to __wait_on_bit() and __wait_on_bit_lock() are
redundant, as the wait_bit_queue parameter holds the flags word and the
bit number. This patch updates __wait_on_bit() and __wait_on_bit_lock()
to fetch that information from the wait_bit_queue passed to them and so
reduce the number of parameters so that -mregparm may be more effective.
Incremental atop the complete out-of-lining of the contention cases and
the fastcall and wait_on_bit_lock()/test_and_set_bit() fixes.
Successfully tested on x86-64.
Index: mm2-2.6.9-rc1/fs/fs-writeback.c
===================================================================
--- mm2-2.6.9-rc1.orig/fs/fs-writeback.c 2004-08-31 01:06:56.824462896 -0700
+++ mm2-2.6.9-rc1/fs/fs-writeback.c 2004-08-31 01:57:17.099311328 -0700
@@ -257,8 +257,8 @@
do {
__iget(inode);
spin_unlock(&inode_lock);
- __wait_on_bit(wqh, &wq, &inode->i_state, __I_LOCK,
- inode_wait, TASK_UNINTERRUPTIBLE);
+ __wait_on_bit(wqh, &wq, inode_wait,
+ TASK_UNINTERRUPTIBLE);
iput(inode);
spin_lock(&inode_lock);
} while (inode->i_state & I_LOCK);
Index: mm2-2.6.9-rc1/include/linux/wait.h
===================================================================
--- mm2-2.6.9-rc1.orig/include/linux/wait.h 2004-08-31 01:50:40.947535552 -0700
+++ mm2-2.6.9-rc1/include/linux/wait.h 2004-08-31 01:54:33.867126392 -0700
@@ -140,8 +140,8 @@
extern void FASTCALL(__wake_up_locked(wait_queue_head_t *q, unsigned int mode));
extern void FASTCALL(__wake_up_sync(wait_queue_head_t *q, unsigned int mode, int nr));
void FASTCALL(__wake_up_bit(wait_queue_head_t *, void *, int));
-int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, void *, int, int (*)(void *), unsigned));
-int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, void *, int, int (*)(void *), unsigned));
+int FASTCALL(__wait_on_bit(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
+int FASTCALL(__wait_on_bit_lock(wait_queue_head_t *, struct wait_bit_queue *, int (*)(void *), unsigned));
void FASTCALL(wake_up_bit(void *, int));
int FASTCALL(out_of_line_wait_on_bit(void *, int, int (*)(void *), unsigned));
int FASTCALL(out_of_line_wait_on_bit_lock(void *, int, int (*)(void *), unsigned));
Index: mm2-2.6.9-rc1/kernel/wait.c
===================================================================
--- mm2-2.6.9-rc1.orig/kernel/wait.c 2004-08-31 01:51:18.966755752 -0700
+++ mm2-2.6.9-rc1/kernel/wait.c 2004-08-31 02:00:10.430960912 -0700
@@ -151,14 +151,14 @@
* permitted return codes. Nonzero return codes halt waiting and return.
*/
int __sched fastcall __wait_on_bit(wait_queue_head_t *wq,
- struct wait_bit_queue *q, void *word,
- int bit, int (*action)(void *), unsigned mode)
+ struct wait_bit_queue *q,
+ int (*action)(void *), unsigned mode)
{
int ret = 0;
prepare_to_wait(wq, &q->wait, mode);
- if (test_bit(bit, word))
- ret = (*action)(word);
+ if (test_bit(q->key.bit_nr, q->key.flags))
+ ret = (*action)(q->key.flags);
finish_wait(wq, &q->wait);
return ret;
}
@@ -170,23 +170,23 @@
wait_queue_head_t *wq = bit_waitqueue(word, bit);
DEFINE_WAIT_BIT(wait, word, bit);
- return __wait_on_bit(wq, &wait, word, bit, action, mode);
+ return __wait_on_bit(wq, &wait, action, mode);
}
EXPORT_SYMBOL(out_of_line_wait_on_bit);
int __sched fastcall __wait_on_bit_lock(wait_queue_head_t *wq,
- struct wait_bit_queue *q, void *word, int bit,
+ struct wait_bit_queue *q,
int (*action)(void *), unsigned mode)
{
int ret = 0;
do {
prepare_to_wait_exclusive(wq, &q->wait, mode);
- if (test_bit(bit, word)) {
- if ((ret = (*action)(word)))
+ if (test_bit(q->key.bit_nr, q->key.flags)) {
+ if ((ret = (*action)(q->key.flags)))
break;
}
- } while (test_and_set_bit(bit, word));
+ } while (test_and_set_bit(q->key.bit_nr, q->key.flags));
finish_wait(wq, &q->wait);
return ret;
}
@@ -198,7 +198,7 @@
wait_queue_head_t *wq = bit_waitqueue(word, bit);
DEFINE_WAIT_BIT(wait, word, bit);
- return __wait_on_bit_lock(wq, &wait, word, bit, action, mode);
+ return __wait_on_bit_lock(wq, &wait, action, mode);
}
EXPORT_SYMBOL(out_of_line_wait_on_bit_lock);
Index: mm2-2.6.9-rc1/mm/filemap.c
===================================================================
--- mm2-2.6.9-rc1.orig/mm/filemap.c 2004-08-31 01:06:56.779469736 -0700
+++ mm2-2.6.9-rc1/mm/filemap.c 2004-08-31 01:59:36.716086352 -0700
@@ -377,8 +377,8 @@
DEFINE_WAIT_BIT(wait, &page->flags, bit_nr);
if (test_bit(bit_nr, &page->flags))
- __wait_on_bit(page_waitqueue(page), &wait, wait.key.flags,
- bit_nr, sync_page, TASK_UNINTERRUPTIBLE);
+ __wait_on_bit(page_waitqueue(page), &wait, sync_page,
+ TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(wait_on_page_bit);
@@ -436,8 +436,8 @@
{
DEFINE_WAIT_BIT(wait, &page->flags, PG_locked);
- __wait_on_bit_lock(page_waitqueue(page), &wait, wait.key.flags,
- PG_locked, sync_page, TASK_UNINTERRUPTIBLE);
+ __wait_on_bit_lock(page_waitqueue(page), &wait, sync_page,
+ TASK_UNINTERRUPTIBLE);
}
EXPORT_SYMBOL(__lock_page);
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
- Previous message: Lee Revell: "Re: [patch] voluntary-preempt-2.6.9-rc1-bk4-Q5"
- Next in thread: William Lee Irwin III: "[3/2] document wake_up_bit()'s requirement for preceding memory barriers"
- Reply: William Lee Irwin III: "[3/2] document wake_up_bit()'s requirement for preceding memory barriers"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
Relevant Pages
|
|
