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mm: convert do_set_pte() to set_pte_range()

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set_pte_range() allows to setup page table entries for a specific
range.  It takes advantage of batched rmap update for large folio.
It now takes care of calling update_mmu_cache_range().

Link: https://lkml.kernel.org/r/20230802151406.3735276-37-willy@infradead.org
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yin Fengwei 2023-08-02 16:14:04 +01:00 committed by Andrew Morton
parent 86f35f69db
commit 3bd786f76d
4 changed files with 28 additions and 17 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
Documentation/filesystems/locking.rst
View file

@ -661,7 +661,7 @@ locked. The VM will unlock the page.
Filesystem should find and map pages associated with offsets from "start_pgoff"
till "end_pgoff". ->map_pages() is called with the RCU lock held and must
not block. If it's not possible to reach a page without blocking,
filesystem should skip it. Filesystem should use do_set_pte() to setup
filesystem should skip it. Filesystem should use set_pte_range() to setup
page table entry. Pointer to entry associated with the page is passed in
"pte" field in vm_fault structure. Pointers to entries for other offsets
should be calculated relative to "pte".

3
include/linux/mm.h
View file

@ -1322,7 +1322,8 @@ static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
}
vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
void set_pte_range(struct vm_fault *vmf, struct folio *folio,
struct page *page, unsigned int nr, unsigned long addr);
vm_fault_t finish_fault(struct vm_fault *vmf);
vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);

3
mm/filemap.c
View file

@ -3501,8 +3501,7 @@ static vm_fault_t filemap_map_folio_range(struct vm_fault *vmf,
ret = VM_FAULT_NOPAGE;
ref_count++;
do_set_pte(vmf, page, addr);
update_mmu_cache(vma, addr, vmf->pte);
set_pte_range(vmf, folio, page, 1, addr);
} while (vmf->pte++, page++, addr += PAGE_SIZE, ++count < nr_pages);
/* Restore the vmf->pte */

37
mm/memory.c
View file

@ -4330,15 +4330,24 @@ vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page)
}
#endif
void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
/**
* set_pte_range - Set a range of PTEs to point to pages in a folio.
* @vmf: Fault decription.
* @folio: The folio that contains @page.
* @page: The first page to create a PTE for.
* @nr: The number of PTEs to create.
* @addr: The first address to create a PTE for.
*/
void set_pte_range(struct vm_fault *vmf, struct folio *folio,
struct page *page, unsigned int nr, unsigned long addr)
{
struct vm_area_struct *vma = vmf->vma;
bool uffd_wp = vmf_orig_pte_uffd_wp(vmf);
bool write = vmf->flags & FAULT_FLAG_WRITE;
bool prefault = vmf->address != addr;
bool prefault = in_range(vmf->address, addr, nr * PAGE_SIZE);
pte_t entry;
flush_icache_page(vma, page);
flush_icache_pages(vma, page, nr);
entry = mk_pte(page, vma->vm_page_prot);
if (prefault && arch_wants_old_prefaulted_pte())
@ -4352,14 +4361,18 @@ void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr)
entry = pte_mkuffd_wp(entry);
/* copy-on-write page */
if (write && !(vma->vm_flags & VM_SHARED)) {
inc_mm_counter(vma->vm_mm, MM_ANONPAGES);
page_add_new_anon_rmap(page, vma, addr);
lru_cache_add_inactive_or_unevictable(page, vma);
add_mm_counter(vma->vm_mm, MM_ANONPAGES, nr);
VM_BUG_ON_FOLIO(nr != 1, folio);
folio_add_new_anon_rmap(folio, vma, addr);
folio_add_lru_vma(folio, vma);
} else {
inc_mm_counter(vma->vm_mm, mm_counter_file(page));
page_add_file_rmap(page, vma, false);
add_mm_counter(vma->vm_mm, mm_counter_file(page), nr);
folio_add_file_rmap_range(folio, page, nr, vma, false);
}
set_pte_at(vma->vm_mm, addr, vmf->pte, entry);
set_ptes(vma->vm_mm, addr, vmf->pte, entry, nr);
/* no need to invalidate: a not-present page won't be cached */
update_mmu_cache_range(vmf, vma, addr, vmf->pte, nr);
}
static bool vmf_pte_changed(struct vm_fault *vmf)
@ -4427,11 +4440,9 @@ vm_fault_t finish_fault(struct vm_fault *vmf)
/* Re-check under ptl */
if (likely(!vmf_pte_changed(vmf))) {
do_set_pte(vmf, page, vmf->address);
/* no need to invalidate: a not-present page won't be cached */
update_mmu_cache(vma, vmf->address, vmf->pte);
struct folio *folio = page_folio(page);
set_pte_range(vmf, folio, page, 1, vmf->address);
ret = 0;
} else {
update_mmu_tlb(vma, vmf->address, vmf->pte);