try_to_free_swap

Name:If swap is getting full, or if there are no more mappings of this page,* then try_to_free_swap is called to free its swap space.

Proto:int try_to_free_swap(struct page *page)

Type:int

Parameter:

Type	Parameter	Name
struct page *	page

1695

VM_BUG_ON_PAGE(!PageLocked(page), page)

1697

If Not PageSwapCache(page) Then Return 0

1699

If Only test-and-set exist for PG_writeback. The unconditional operators are* risky: they bypass page accounting. Then Return 0

1701

If page_swapped(page) Then Return 0

1719

If pm_suspended_storage() Then Return 0

1722

page = compound_head(page)

1723

This must be called only on pages that have* been verified to be in the swap cache and locked.* It will never put the page into the free list,* the caller has a reference on the page.

1724

SetPageDirty(page)

1725

Return 1

**Caller**
Name	Describe
do_swap_page	We enter with non-exclusive mmap_sem (to exclude vma changes,* but allow concurrent faults), and pte mapped but not yet locked.* We return with pte unmapped and unlocked.* We return with the mmap_sem locked or unlocked in the same cases
madvise_free_pte_range
swap_writepage	We may have stale swap cache pages in memory: notice* them here and get rid of the unnecessary final write.
free_swap_cache	If we are the only user, then try to free up the swap cache. * Its ok to check for PageSwapCache without the page lock* here because we are going to recheck again inside* try_to_free_swap() _with_ the lock.* - Marcelo
__try_to_reclaim_swap	rns 1 if swap entry is freed
unuse_pte_range
try_to_unuse	If the boolean frontswap is true, only unuse pages_to_unuse pages;* pages_to_unuse==0 means all pages; ignored if frontswap is false
replace_page	place_page - replace page in vma by new ksm page@vma: vma that holds the pte pointing to page@page: the page we are replacing by kpage@kpage: the ksm page we replace page by@orig_pte: the original value of the pte

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