Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:mm\hugetlb.c Create Date:2022-07-28 15:28:38
Last Modify:2020-03-12 14:18:49 Copyright©Brick
home page Tree
Annotation kernel can get tool activityDownload SCCTChinese

Name:Hugetlb_cow() should be called with page lock of the original hugepage held.* Called with hugetlb_instantiation_mutex held and pte_page locked so we* cannot race with other handlers or page migration.

Proto:static vm_fault_t hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma, unsigned long address, pte_t *ptep, struct page *pagecache_page, spinlock_t *ptl)

Type:vm_fault_t

Parameter:

TypeParameterName
struct mm_struct *mm
struct vm_area_struct *vma
unsigned longaddress
pte_t *ptep
struct page *pagecache_page
spinlock_t *ptl
3613  h = hstate_vma(vma)
3615  outside_reserve = 0
3616  ret = 0
3617  haddr = address & huge_page_mask(h)
3620  pte = huge_ptep_get(ptep)
3621  old_page = pte_page(pte)
3623  retry_avoidcopy :
3626  If page_mapcount(old_page) == 1 && PageAnon(old_page) Then
3627  page_move_anon_rmap - move a page to our anon_vma*@page: the page to move to our anon_vma*@vma: the vma the page belongs to* When a page belongs exclusively to one process after a COW event,* that page can be moved into the anon_vma that belongs to just
3628  set_huge_ptep_writable(vma, haddr, ptep)
3629  Return 0
3641  If is_vma_resv_set(vma, Flags for MAP_PRIVATE reservations. These are stored in the bottom* bits of the reservation map pointer, which are always clear due to* alignment.) && old_page != pagecache_page Then outside_reserve = 1
3645  get_page(old_page)
3651  spin_unlock(ptl)
3652  new_page = alloc_huge_page(vma, haddr, outside_reserve)
3654  If IS_ERR(new_page) Then
3662  If outside_reserve Then
3663  Perform a free_page(), also freeing any swap cache associated with* this page if it is the last user of the page.
3664  BUG_ON(huge_pte_none(pte))
3665  This is called when the original mapper is failing to COW a MAP_PRIVATE* mappping it owns the reserve page for. The intention is to unmap the page* from other VMAs and let the children be SIGKILLed if they are faulting the* same region.
3666  BUG_ON(huge_pte_none(pte))
3667  spin_lock(ptl)
3668  ptep = huge_pte_offset(mm, haddr, huge_page_size(h))
3669  If Value is more likely to compile time(ptep && pte_same(huge_ptep_get(ptep), pte)) Then Go to retry_avoidcopy
3676  Return 0
3679  ret = vmf_error(PTR_ERR(new_page))
3680  Go to out_release_old
3687  If Value for the false possibility is greater at compile time(anon_vma_prepare(vma)) Then
3688  ret = VM_FAULT_OOM
3689  Go to out_release_all
3692  copy_user_huge_page(new_page, old_page, address, vma, pages_per_huge_page(h))
3694  __SetPageUptodate(new_page)
3696  mmu_notifier_range_init( & range, MMU_NOTIFY_CLEAR, 0, vma, mm, haddr, haddr + huge_page_size(h))
3698  mmu_notifier_invalidate_range_start( & range)
3704  spin_lock(ptl)
3705  ptep = huge_pte_offset(mm, haddr, huge_page_size(h))
3706  If Value is more likely to compile time(ptep && pte_same(huge_ptep_get(ptep), pte)) Then
3707  Private page markings that may be used by the filesystem that owns the page* for its own purposes.* - PG_private and PG_private_2 cause releasepage() and co to be invoked
3710  huge_ptep_clear_flush(vma, haddr, ptep)
3711  mmu_notifier_invalidate_range(mm, start, end)
3712  set_huge_pte_at(mm, haddr, ptep, make_huge_pte(vma, new_page, 1))
3714  page_remove_rmap - take down pte mapping from a page*@page: page to remove mapping from*@compound: uncharge the page as compound or small page* The caller needs to hold the pte lock.
3715  hugepage_add_new_anon_rmap(new_page, vma, haddr)
3716  ver called for tail page
3718  new_page = old_page
3720  spin_unlock(ptl)
3721  mmu_notifier_invalidate_range_end( & range)
3722  out_release_all :
3723  This routine is called to restore a reservation on error paths
3724  Perform a free_page(), also freeing any swap cache associated with* this page if it is the last user of the page.
3725  out_release_old :
3726  Perform a free_page(), also freeing any swap cache associated with* this page if it is the last user of the page.
3728  spin_lock(ptl)
3729  Return ret
Caller
NameDescribe
hugetlb_no_page
hugetlb_fault