change_pte

函数名称：change_pte_range

函数原型：static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, unsigned long addr, unsigned long end, pgprot_t newprot, int dirty_accountable, int prot_numa)

返回类型：unsigned long

参数：

类型	参数	名称
struct vm_area_struct *	vma
pmd_t *	pmd
unsigned long	addr
unsigned long	end
pgprot_t	newprot
int	dirty_accountable
int	prot_numa

oldpte等于pte

如果pte_present(oldpte)则

preserve_write等于prot_numa且pte_write(oldpte)

如果prot_numa则

如果Technically a PTE can be PROTNONE even when not doing NUMA balancing but* the only case the kernel cares is for NUMA balancing and is only ever set* when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked则继续下一循环

page等于vm_normal_page -- This function gets the "struct page" associated with a pte.* "Special" mappings do not wish to be associated with a "struct page" (either* it doesn't exist, or it exists but they don't want to touch it). In this

如果非page或A KSM page is one of those write-protected "shared pages" or "merged pages"* which KSM maps into multiple mms, wherever identical anonymous page content* is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any则继续下一循环

如果is_cow_mapping(Flags, see mm.h. )且page_mapcount(page)不等于1则继续下一循环

101

如果page_is_file_cache - should the page be on a file LRU or anon LRU?*@page: the page to test* Returns 1 if @page is page cache page backed by a regular filesystem,* or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed且PageDirty(page)则继续下一循环

108

如果target_node恒等于page_to_nid(page)则继续下一循环

112

oldpte等于Start a pte protection read-modify-write transaction, which* protects against asynchronous hardware modifications to the pte

113

ptent等于pte_modify(oldpte, newprot)

114

如果preserve_write则ptent等于pte_mk_savedwrite(ptent)

118

如果dirty_accountable且The following only work if pte_present() is true.* Undefined behaviour if not..且pte_soft_dirty(ptent)或非Flags, see mm.h. 按位与VM_SOFTDIRTY的值的值则

121

ptent等于pte_mkwrite(ptent)

123

Commit an update to a pte, leaving any hardware-controlled bits in* the PTE unmodified.

124

pages自加

125

否则如果IS_ENABLED(CONFIG_FOO) evaluates to 1 if CONFIG_FOO is set to 'y' or 'm',* 0 otherwise.(CONFIG_MIGRATION)则

126

entry等于Convert the arch-dependent pte representation of a swp_entry_t into an* arch-independent swp_entry_t.

128

如果is_write_migration_entry(entry)则

134

make_migration_entry_read( & entry)

135

newpte等于Convert the arch-independent representation of a swp_entry_t into the* arch-dependent pte representation.

136

如果pte_swp_soft_dirty(oldpte)则newpte等于pte_swp_mksoft_dirty(newpte)

138

set_pte_at(The address space we belong to. , addr, pte, newpte)

140

pages自加

143

如果is_write_device_private_entry(entry)则

150

make_device_private_entry_read( & entry)

151

newpte等于Convert the arch-independent representation of a swp_entry_t into the* arch-dependent pte representation.

152

set_pte_at(The address space we belong to. , addr, pte, newpte)

154

pages自加

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