Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\filemap.c Create Date:2022-07-28 14:01:45
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:page_cache_prev_miss() - Find the previous gap in the page cache.*@mapping: Mapping.*@index: Index.*@max_scan: Maximum range to search.* Search the range [max(index - max_scan + 1, 0), index] for the* gap with the highest index.

Proto:unsigned long page_cache_prev_miss(struct address_space *mapping, unsigned long index, unsigned long max_scan)

Type:unsigned long

Parameter:

TypeParameterName
struct address_space *mapping
unsigned longindex
unsigned longmax_scan
1498  XA_STATE() - Declare an XArray operation state.*@name: Name of this operation state (usually xas).*@array: Array to operate on.*@index: Initial index of interest.* Declare and initialise an xa_state on the stack.(xas, & i_pages, index)
1500  When max_scan-- cycle
1501  entry = xas_prev() - Move iterator to previous index.*@xas: XArray operation state.* If the @xas was in an error state, it will remain in an error state* and this function will return %NULL. If the @xas has never been walked,
1502  If Not entry || xa_is_value() - Determine if an entry is a value.*@entry: XArray entry.* Context: Any context.* Return: True if the entry is a value, false if it is a pointer. Then Break
1504  If xa_index == ULONG_MAX Then Break
1508  Return xa_index
Caller
NameDescribe
count_history_pagesCount contiguously cached pages from @offset-1 to @offset-@max,* this count is a conservative estimation of* - length of the sequential read sequence, or* - thrashing threshold in memory tight systems