Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\swapfile.c Create Date:2022-07-28 15:17:43
Last Modify:2020-03-17 22:19:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:How many references to page are currently swapped out?* This does not give an exact answer when swap count is continued,* but does include the high COUNT_CONTINUED flag to allow for that.

Proto:int page_swapcount(struct page *page)

Type:int

Parameter:

TypeParameterName
struct page *page
1431  count = 0
1437  val = page_private(page)
1438  p = _swap_info_get(entry)
1439  If p Then
1440  offset = Extract the `offset' field from a swp_entry_t. The swp_entry_t is in* arch-independent format
1441  ci = Determine the locking method in use for this device. Return* swap_cluster_info if SSD-style cluster-based locking is in place.
1442  count = swap_count(vmalloc'ed array of usage counts [offset])
1443  unlock_cluster_or_swap_info(p, ci)
1445  Return count
Caller
NameDescribe
page_swapped
page_trans_huge_map_swapcount
reuse_swap_pageWe can write to an anon page without COW if there are no other references* to it. And as a side-effect, free up its swap: because the old content* on disk will never be read, and seeking back there to write new content