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charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: DE0991C0015 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: g4qu5rr8jk699d53n6f7mq6kewgchdyx X-HE-Tag: 1701084635-473712 X-HE-Meta: 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 IsEGl3Wr uUBLLrvIm6oZ007tG5xQFrkOiVQvY9tE1ZwMW7/6quw6HrOH/WJEzn6SQf4wVmhlHcEVBVZtAndkirVMmQOK/oTEZc/mWrWxT/roP7rHI3lJT6a+zOrK5sKuyb8ifKyVKjjodY2kHwogkg0VvrSxERQZHkfzu2ExuB+upNbzFTeubqMYRJb2wBJqFxAQPskikYvxhyjNr1ymZU56v2JLTRaGWxgDj1g7FtwNpEYkl5R2ryqREmzuBmT9Y1/vKdifn9kqXyngzZzG0VD4= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 27/11/2023 04:36, Barry Song wrote: >> 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); > > Hi Ryan, > > we are doing an entire mapping, right? what is the reason to > increase mapcount for each subpage? shouldn't we only increase > mapcount of subpage in either split or doublemap case? > > in page_add_anon_rmap(), are we also increasing mapcount of > each subpage for fork() case where the entire large folio > is inheritted by child processes? I think this is all answered by the conversation we just had in the context of the contpte series? Let me know if you still have concerns. > >> + } >> + >> + 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); >> } > > Thanks > Barry >