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. * This is exported only for wait_on_page_locked/wait_on_page_writeback,
* Never use this directly! * and for filesystems which need to wait on PG_private.
*/ */
extern void wait_on_page_bit(struct page *page, int bit_nr); 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; 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. * 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 * at a cost of "thundering herd" phenomena during rare hash
* collisions. * 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); const struct zone *zone = page_zone(page);
return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)]; return &zone->wait_table[hash_ptr(page, zone->wait_table_bits)];
} }
EXPORT_SYMBOL(page_waitqueue);
static inline void wake_up_page(struct page *page, int bit)
{
__wake_up_bit(page_waitqueue(page), &page->flags, bit);
}
void wait_on_page_bit(struct page *page, int bit_nr) void wait_on_page_bit(struct page *page, int bit_nr)
{ {