From cbbce82209490df8b68da9aec0d642451fe0a668 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Thu, 25 Sep 2014 13:55:19 +1000 Subject: SCHED: add some "wait..on_bit...timeout()" interfaces. In commit c1221321b7c25b53204447cff9949a6d5a7ddddc sched: Allow wait_on_bit_action() functions to support a timeout I suggested that a "wait_on_bit_timeout()" interface would not meet my need. This isn't true - I was just over-engineering. Including a 'private' field in wait_bit_key instead of a focused "timeout" field was just premature generalization. If some other use is ever found, it can be generalized or added later. So this patch renames "private" to "timeout" with a meaning "stop waiting when "jiffies" reaches or passes "timeout", and adds two of the many possible wait..bit..timeout() interfaces: wait_on_page_bit_killable_timeout(), which is the one I want to use, and out_of_line_wait_on_bit_timeout() which is a reasonably general example. Others can be added as needed. Acked-by: Peter Zijlstra (Intel) Signed-off-by: NeilBrown Acked-by: Ingo Molnar Signed-off-by: Trond Myklebust --- mm/filemap.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) (limited to 'mm/filemap.c') diff --git a/mm/filemap.c b/mm/filemap.c index 90effcdf948d..cbe5a9013f70 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -703,6 +703,19 @@ int wait_on_page_bit_killable(struct page *page, int bit_nr) bit_wait_io, TASK_KILLABLE); } +int wait_on_page_bit_killable_timeout(struct page *page, + int bit_nr, unsigned long timeout) +{ + DEFINE_WAIT_BIT(wait, &page->flags, bit_nr); + + wait.key.timeout = jiffies + timeout; + if (!test_bit(bit_nr, &page->flags)) + return 0; + return __wait_on_bit(page_waitqueue(page), &wait, + bit_wait_io_timeout, TASK_KILLABLE); +} +EXPORT_SYMBOL_GPL(wait_on_page_bit_killable_timeout); + /** * add_page_wait_queue - Add an arbitrary waiter to a page's wait queue * @page: Page defining the wait queue of interest -- cgit v1.2.3 From a4796e37c12e177572b80864cbab9c907ea250b0 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Wed, 24 Sep 2014 11:28:32 +1000 Subject: 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 Acked-by: Andrew Morton Signed-off-by: Trond Myklebust --- include/linux/pagemap.h | 10 ++++++++-- mm/filemap.c | 8 ++------ 2 files changed, 10 insertions(+), 8 deletions(-) (limited to 'mm/filemap.c') diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 87f9e4230d3a..2dca0cef3506 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -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. * diff --git a/mm/filemap.c b/mm/filemap.c index cbe5a9013f70..b9b1413080be 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -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) { -- cgit v1.2.3