MM: export page_wakeup functions

This will allow NFS to wait for PG_private to be cleared and,
particularly, to send a wake-up when it is.

Signed-off-by: NeilBrown <neilb@suse.de>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
This commit is contained in:
NeilBrown 2014-09-24 11:28:32 +10:00 committed by Trond Myklebust
parent cbbce82209
commit a4796e37c1
2 changed files with 10 additions and 8 deletions

View File

@ -496,8 +496,8 @@ static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
}
/*
* This is exported only for wait_on_page_locked/wait_on_page_writeback.
* Never use this directly!
* This is exported only for wait_on_page_locked/wait_on_page_writeback,
* and for filesystems which need to wait on PG_private.
*/
extern void wait_on_page_bit(struct page *page, int bit_nr);
@ -512,6 +512,12 @@ static inline int wait_on_page_locked_killable(struct page *page)
return 0;
}
extern wait_queue_head_t *page_waitqueue(struct page *page);
static inline void wake_up_page(struct page *page, int bit)
{
__wake_up_bit(page_waitqueue(page), &page->flags, bit);
}
/*
* Wait for a page to be unlocked.
*

View File

@ -670,17 +670,13 @@ EXPORT_SYMBOL(__page_cache_alloc);
* at a cost of "thundering herd" phenomena during rare hash
* collisions.
*/
static wait_queue_head_t *page_waitqueue(struct page *page)
wait_queue_head_t *page_waitqueue(struct page *page)
{
const struct zone *zone = page_zone(page);
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);
}
EXPORT_SYMBOL(page_waitqueue);
void wait_on_page_bit(struct page *page, int bit_nr)
{