| Message ID | 20231204102027.57185-3-ryan.roberts@arm.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Multi-size THP for anonymous memory | expand |
On Mon, Dec 4, 2023 at 6:20 PM Ryan Roberts <ryan.roberts@arm.com> wrote: > > In preparation for supporting anonymous multi-size THP, improve > folio_add_new_anon_rmap() to allow a non-pmd-mappable, large folio to be > passed to it. In this case, all contained pages are accounted using the > order-0 folio (or base page) scheme. > > Reviewed-by: Yu Zhao <yuzhao@google.com> > Reviewed-by: Yin Fengwei <fengwei.yin@intel.com> > Reviewed-by: David Hildenbrand <david@redhat.com> > Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Reviewed-by: Barry Song <v-songbaohua@oppo.com> > --- > mm/rmap.c | 28 ++++++++++++++++++++-------- > 1 file changed, 20 insertions(+), 8 deletions(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 2a1e45e6419f..846fc79f3ca9 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1335,32 +1335,44 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, > * This means the inc-and-test can be bypassed. > * The folio does not have to be locked. > * > - * If the folio is large, it is accounted as a THP. As the folio > + * If the folio is pmd-mappable, it is accounted as a THP. As the folio > * is new, it's assumed to be mapped exclusively by a single process. > */ > void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, > unsigned long address) > { > - int nr; > + int nr = folio_nr_pages(folio); > > - VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); > + VM_BUG_ON_VMA(address < vma->vm_start || > + address + (nr << PAGE_SHIFT) > vma->vm_end, vma); > __folio_set_swapbacked(folio); > + __folio_set_anon(folio, vma, address, true); > > - if (likely(!folio_test_pmd_mappable(folio))) { > + if (likely(!folio_test_large(folio))) { > /* increment count (starts at -1) */ > atomic_set(&folio->_mapcount, 0); > - nr = 1; > + SetPageAnonExclusive(&folio->page); > + } else if (!folio_test_pmd_mappable(folio)) { > + int i; > + > + for (i = 0; i < nr; i++) { > + struct page *page = folio_page(folio, i); > + > + /* increment count (starts at -1) */ > + atomic_set(&page->_mapcount, 0); > + SetPageAnonExclusive(page); > + } > + > + atomic_set(&folio->_nr_pages_mapped, nr); > } else { > /* increment count (starts at -1) */ > atomic_set(&folio->_entire_mapcount, 0); > atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED); > - nr = folio_nr_pages(folio); > + SetPageAnonExclusive(&folio->page); > __lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr); > } > > __lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr); > - __folio_set_anon(folio, vma, address, true); > - SetPageAnonExclusive(&folio->page); > } > > /** > -- > 2.25.1 >
diff --git a/mm/rmap.c b/mm/rmap.c index 2a1e45e6419f..846fc79f3ca9 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1335,32 +1335,44 @@ void page_add_anon_rmap(struct page *page, struct vm_area_struct *vma, * This means the inc-and-test can be bypassed. * The folio does not have to be locked. * - * If the folio is large, it is accounted as a THP. As the folio + * If the folio is pmd-mappable, it is accounted as a THP. As the folio * is new, it's assumed to be mapped exclusively by a single process. */ void folio_add_new_anon_rmap(struct folio *folio, struct vm_area_struct *vma, unsigned long address) { - int nr; + int nr = folio_nr_pages(folio); - VM_BUG_ON_VMA(address < vma->vm_start || address >= vma->vm_end, vma); + VM_BUG_ON_VMA(address < vma->vm_start || + address + (nr << PAGE_SHIFT) > vma->vm_end, vma); __folio_set_swapbacked(folio); + __folio_set_anon(folio, vma, address, true); - if (likely(!folio_test_pmd_mappable(folio))) { + if (likely(!folio_test_large(folio))) { /* increment count (starts at -1) */ atomic_set(&folio->_mapcount, 0); - nr = 1; + SetPageAnonExclusive(&folio->page); + } else if (!folio_test_pmd_mappable(folio)) { + int i; + + for (i = 0; i < nr; i++) { + struct page *page = folio_page(folio, i); + + /* increment count (starts at -1) */ + atomic_set(&page->_mapcount, 0); + SetPageAnonExclusive(page); + } + + atomic_set(&folio->_nr_pages_mapped, nr); } else { /* increment count (starts at -1) */ atomic_set(&folio->_entire_mapcount, 0); atomic_set(&folio->_nr_pages_mapped, COMPOUND_MAPPED); - nr = folio_nr_pages(folio); + SetPageAnonExclusive(&folio->page); __lruvec_stat_mod_folio(folio, NR_ANON_THPS, nr); } __lruvec_stat_mod_folio(folio, NR_ANON_MAPPED, nr); - __folio_set_anon(folio, vma, address, true); - SetPageAnonExclusive(&folio->page); } /**