Messages in this thread Patch in this message | | | Date | Sat, 28 Aug 2004 13:09:51 -0700 | From | William Lee Irwin III <> | Subject | [3/5] consolidate bit waiting code patterns |
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On Sat, Aug 28, 2004 at 01:08:41PM -0700, William Lee Irwin III wrote: > Eliminate specialized page and bh waitqueue hashing structures in favor > of a standardized structure, using wake_up_bit() to wake waiters using > the standardized wait_bit_key structure.
Consolidate bit waiting code patterns for page waitqueues using __wait_on_bit() and __wait_on_bit_lock().
Index: wait-2.6.9-rc1-mm1/kernel/wait.c =================================================================== --- wait-2.6.9-rc1-mm1.orig/kernel/wait.c 2004-08-28 09:48:39.109023976 -0700 +++ wait-2.6.9-rc1-mm1/kernel/wait.c 2004-08-28 09:49:23.070340840 -0700 @@ -143,6 +143,43 @@ } EXPORT_SYMBOL(wake_bit_function); +/* + * To allow interruptible waiting and asynchronous (i.e. nonblocking) + * waiting, the actions of __wait_on_bit() and __wait_on_bit_lock() are + * permitted return codes. Nonzero return codes halt waiting and return. + */ +int __sched __wait_on_bit(wait_queue_head_t *wq, struct wait_bit_queue *q, + void *word, + int bit, int (*action)(void *), unsigned mode) +{ + int ret = 0; + + prepare_to_wait(wq, &q->wait, mode); + if (test_bit(bit, word)) + ret = (*action)(word); + finish_wait(wq, &q->wait); + return ret; +} +EXPORT_SYMBOL(__wait_on_bit); + +int __sched __wait_on_bit_lock(wait_queue_head_t *wq, struct wait_bit_queue *q, + void *word, int bit, + int (*action)(void *), unsigned mode) +{ + int ret = 0; + + while (test_and_set_bit(bit, word)) { + prepare_to_wait_exclusive(wq, &q->wait, mode); + if (test_bit(bit, word)) { + if ((ret = (*action)(word))) + break; + } + } + finish_wait(wq, &q->wait); + return ret; +} +EXPORT_SYMBOL(__wait_on_bit_lock); + void fastcall __wake_up_bit(wait_queue_head_t *wq, void *word, int bit) { struct wait_bit_key key = __WAIT_BIT_KEY_INITIALIZER(word, bit); Index: wait-2.6.9-rc1-mm1/mm/filemap.c =================================================================== --- wait-2.6.9-rc1-mm1.orig/mm/filemap.c 2004-08-28 09:48:39.118022608 -0700 +++ wait-2.6.9-rc1-mm1/mm/filemap.c 2004-08-28 09:49:23.068341144 -0700 @@ -132,9 +132,11 @@ } EXPORT_SYMBOL(remove_from_page_cache); -static inline int sync_page(struct page *page) +static int sync_page(void *word) { struct address_space *mapping; + struct page *page + = container_of((page_flags_t *)word, struct page, flags); /* * FIXME, fercrissake. What is this barrier here for? @@ -142,7 +144,8 @@ smp_mb(); mapping = page_mapping(page); if (mapping && mapping->a_ops && mapping->a_ops->sync_page) - return mapping->a_ops->sync_page(page); + mapping->a_ops->sync_page(page); + io_schedule(); return 0; } @@ -362,19 +365,19 @@ return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)]; } +static inline void wake_up_page(struct page *page, int bit) +{ + __wake_up_bit(page_waitqueue(page), &page->flags, bit); +} + void fastcall wait_on_page_bit(struct page *page, int bit_nr) { - wait_queue_head_t *waitqueue = page_waitqueue(page); DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); - prepare_to_wait(waitqueue, &wait.wait, TASK_UNINTERRUPTIBLE); - if (test_bit(bit_nr, &page->flags)) { - sync_page(page); - io_schedule(); - } - finish_wait(waitqueue, &wait.wait); + if (test_bit(bit_nr, &page->flags)) + __wait_on_bit(page_waitqueue(page), &wait, wait.key.flags, + bit_nr, sync_page, TASK_UNINTERRUPTIBLE); } - EXPORT_SYMBOL(wait_on_page_bit); /** @@ -398,7 +401,7 @@ if (!TestClearPageLocked(page)) BUG(); smp_mb__after_clear_bit(); - __wake_up_bit(page_waitqueue(page), &page->flags, PG_locked); + wake_up_page(page, PG_locked); } EXPORT_SYMBOL(unlock_page); @@ -414,7 +417,7 @@ BUG(); smp_mb__after_clear_bit(); } - __wake_up_bit(page_waitqueue(page), &page->flags, PG_writeback); + wake_up_page(page, PG_writeback); } EXPORT_SYMBOL(end_page_writeback); @@ -429,19 +432,11 @@ */ void fastcall __lock_page(struct page *page) { - wait_queue_head_t *wqh = page_waitqueue(page); DEFINE_WAIT_BIT(wait, &page->flags, PG_locked); - while (TestSetPageLocked(page)) { - prepare_to_wait_exclusive(wqh, &wait.wait, TASK_UNINTERRUPTIBLE); - if (PageLocked(page)) { - sync_page(page); - io_schedule(); - } - } - finish_wait(wqh, &wait.wait); + __wait_on_bit_lock(page_waitqueue(page), &wait, wait.key.flags, + PG_locked, sync_page, TASK_UNINTERRUPTIBLE); } - EXPORT_SYMBOL(__lock_page); /* Index: wait-2.6.9-rc1-mm1/include/linux/wait.h =================================================================== --- wait-2.6.9-rc1-mm1.orig/include/linux/wait.h 2004-08-28 09:48:39.121022152 -0700 +++ wait-2.6.9-rc1-mm1/include/linux/wait.h 2004-08-28 09:49:23.059342512 -0700 @@ -139,6 +139,8 @@ 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)); #define wake_up(x) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, 1, NULL) #define wake_up_nr(x, nr) __wake_up(x, TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, nr, NULL) - 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/
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