Add heavy locking API's for the few cases that a thread needs exclusive
access to an LRU list. This locks lru_lock as well as every lock in
lru_batch_locks.
This API will be used often at first, in scaffolding code, to ease the
transition from using lru_lock to the batch locking scheme. Later it
will be rarely needed.
Signed-off-by: Daniel Jordan <daniel.m.jor...@oracle.com>
---
include/linux/mm_inline.h | 32 ++++++++++++++++++++++++++++++++
1 file changed, 32 insertions(+)
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index ec8b966a1c76..1f1657c75b1b 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -178,6 +178,38 @@ static __always_inline void
move_page_to_lru_list_tail(struct page *page,
__add_page_to_lru_list_tail(page, lruvec, lru);
}
+static __always_inline void lru_lock_all(struct pglist_data *pgdat,
+ unsigned long *flags)
+{
+ size_t i;
+
+ if (flags)
+ local_irq_save(*flags);
+ else
+ local_irq_disable();
+
+ for (i = 0; i < NUM_LRU_BATCH_LOCKS; ++i)
+ spin_lock(&pgdat->lru_batch_locks[i].lock);
+
+ spin_lock(&pgdat->lru_lock);
+}
+
+static __always_inline void lru_unlock_all(struct pglist_data *pgdat,
+ unsigned long *flags)
+{
+ int i;
+
+ spin_unlock(&pgdat->lru_lock);
+
+ for (i = NUM_LRU_BATCH_LOCKS - 1; i >= 0; --i)
+ spin_unlock(&pgdat->lru_batch_locks[i].lock);
+
+ if (flags)
+ local_irq_restore(*flags);
+ else
+ local_irq_enable();
+}
+
/**
* page_lru_base_type - which LRU list type should a page be on?
* @page: the page to test
--
2.16.1
