| Message ID | 20230201081737.2330141-4-fengwei.yin@intel.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | folio based filemap_map_pages() | expand |
On Wed, Feb 01, 2023 at 04:17:35PM +0800, Yin Fengwei wrote: > /** > - * page_add_file_rmap - add pte mapping to a file page > - * @page: the page to add the mapping to > + * page_add_file_rmap_range - add pte mapping to a sub page range of a folio > + * @folio: The filio to add the mapping to > + * @start: The first sub page index in folio > + * @nr_pages: The number of sub pages from the first page > * @vma: the vm area in which the mapping is added > * @compound: charge the page as compound or small page > * > + * The sub page range of folio is defined by > + * [first_sub_page, first_sub_page + nr_pages) Lose the "sub" from all of this. That's legacy thinking; pages are pages and folios are folios. "subpages" was from when we were trying to use the word "page" for both "the allocation" and "the PAGE_SIZE range of bytes". > + * > * The caller needs to hold the pte lock. > */ > -void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, > - bool compound) > +void page_add_file_rmap_range(struct folio *folio, unsigned long start, > + unsigned int nr_pages, struct vm_area_struct *vma, > + bool compound) I think this function needs to be called folio_add_file_rmap() I'd like to lose the 'compound' parameter, and base it on nr_pages == folio_nr_pages(), but that may be a step far just now.
On 2/2/2023 1:32 AM, Matthew Wilcox wrote: > On Wed, Feb 01, 2023 at 04:17:35PM +0800, Yin Fengwei wrote: >> /** >> - * page_add_file_rmap - add pte mapping to a file page >> - * @page: the page to add the mapping to >> + * page_add_file_rmap_range - add pte mapping to a sub page range of a folio >> + * @folio: The filio to add the mapping to >> + * @start: The first sub page index in folio >> + * @nr_pages: The number of sub pages from the first page >> * @vma: the vm area in which the mapping is added >> * @compound: charge the page as compound or small page >> * >> + * The sub page range of folio is defined by >> + * [first_sub_page, first_sub_page + nr_pages) > > Lose the "sub" from all of this. That's legacy thinking; pages are > pages and folios are folios. "subpages" was from when we were trying > to use the word "page" for both "the allocation" and "the PAGE_SIZE > range of bytes". OK. Will remove sub in next version. > >> + * >> * The caller needs to hold the pte lock. >> */ >> -void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, >> - bool compound) >> +void page_add_file_rmap_range(struct folio *folio, unsigned long start, >> + unsigned int nr_pages, struct vm_area_struct *vma, >> + bool compound) > > I think this function needs to be called folio_add_file_rmap() Yes. Maybe a followup patch after this series? Let me know if you want this change in this series. > > I'd like to lose the 'compound' parameter, and base it on nr_pages == > folio_nr_pages(), but that may be a step far just now. Yes. I had a local change to remove if (folio_test_pmd_mappable(folio)) test (It's very close to removing 'compound'). I didn't include it in this series. I prefer a follow up patch. Let me know if you want the change in this series. Thanks. Regards Yin, Fengwei >
diff --git a/include/linux/rmap.h b/include/linux/rmap.h index a4570da03e58..9631a3701504 100644 --- a/include/linux/rmap.h +++ b/include/linux/rmap.h @@ -198,6 +198,8 @@ void folio_add_new_anon_rmap(struct folio *, struct vm_area_struct *, unsigned long address); void page_add_file_rmap(struct page *, struct vm_area_struct *, bool compound); +void page_add_file_rmap_range(struct folio *, unsigned long start, + unsigned int nr_pages, struct vm_area_struct *, bool compound); void page_remove_rmap(struct page *, struct vm_area_struct *, bool compound); diff --git a/mm/rmap.c b/mm/rmap.c index 15ae24585fc4..090de52e1a9a 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1303,31 +1303,44 @@ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, } /** - * page_add_file_rmap - add pte mapping to a file page - * @page: the page to add the mapping to + * page_add_file_rmap_range - add pte mapping to a sub page range of a folio + * @folio: The filio to add the mapping to + * @start: The first sub page index in folio + * @nr_pages: The number of sub pages from the first page * @vma: the vm area in which the mapping is added * @compound: charge the page as compound or small page * + * The sub page range of folio is defined by + * [first_sub_page, first_sub_page + nr_pages) + * * The caller needs to hold the pte lock. */ -void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, - bool compound) +void page_add_file_rmap_range(struct folio *folio, unsigned long start, + unsigned int nr_pages, struct vm_area_struct *vma, + bool compound) { - struct folio *folio = page_folio(page); atomic_t *mapped = &folio->_nr_pages_mapped; - int nr = 0, nr_pmdmapped = 0; - bool first; + unsigned int nr = 0, nr_pmdmapped = 0, first; - VM_BUG_ON_PAGE(compound && !PageTransHuge(page), page); + VM_WARN_ON_FOLIO(compound && !folio_test_pmd_mappable(folio), folio); /* Is page being mapped by PTE? Is this its first map to be added? */ if (likely(!compound)) { - first = atomic_inc_and_test(&page->_mapcount); - nr = first; - if (first && folio_test_large(folio)) { - nr = atomic_inc_return_relaxed(mapped); - nr = (nr < COMPOUND_MAPPED); - } + struct page *page = folio_page(folio, start); + + nr_pages = min_t(unsigned int, nr_pages, + folio_nr_pages(folio) - start); + + do { + first = atomic_inc_and_test(&page->_mapcount); + if (first && folio_test_large(folio)) { + first = atomic_inc_return_relaxed(mapped); + first = (nr < COMPOUND_MAPPED); + } + + if (first) + nr++; + } while (page++, --nr_pages > 0); } else if (folio_test_pmd_mappable(folio)) { /* That test is redundant: it's for safety or to optimize out */ @@ -1356,6 +1369,31 @@ void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, mlock_vma_folio(folio, vma, compound); } +/** + * page_add_file_rmap - add pte mapping to a file page + * @page: the page to add the mapping to + * @vma: the vm area in which the mapping is added + * @compound: charge the page as compound or small page + * + * The caller needs to hold the pte lock. + */ +void page_add_file_rmap(struct page *page, struct vm_area_struct *vma, + bool compound) +{ + struct folio *folio = page_folio(page); + unsigned int nr_pages; + + VM_WARN_ON_ONCE_PAGE(compound && !PageTransHuge(page), page); + + if (likely(!compound)) + nr_pages = 1; + else + nr_pages = folio_nr_pages(folio); + + page_add_file_rmap_range(folio, folio_page_idx(folio, page), + nr_pages, vma, compound); +} + /** * page_remove_rmap - take down pte mapping from a page * @page: page to remove mapping from
page_add_file_rmap_range() allows to add pte mapping to a specific range of file folio. Comparing to original page_add_file_rmap(), it batched updates __lruvec_stat for large folio. Signed-off-by: Yin Fengwei <fengwei.yin@intel.com> --- include/linux/rmap.h | 2 ++ mm/rmap.c | 66 ++++++++++++++++++++++++++++++++++---------- 2 files changed, 54 insertions(+), 14 deletions(-)