page_pgoff(9)

💅 page_pgoff(9) — from the Kernel API Manual, bestie

okay so this page is literally about page_pgoff, which calculates the logical page offset of this page. that's the whole vibe. it lives in the Kernel API Manual and we're gonna get into it ✨

---

🌸 NAME 🌸

page_pgoff — calculate the logical page offset of this page. that's it, that's the job 🎀

---

✨ SYNOPSIS ✨

pgoff_t page_pgoff (const struct folio *folio , const struct page *page
);

look at her. two consts, one return type, zero notes. iconic 🫶

---

🦋 ARGUMENTS 🦋

• folio — the folio that's holding this page. your container, your home base 💖
• page — the page whose offset we're out here trying to find. yes her specifically 👑

---

🌈 DESCRIPTION 🌈

okay so this is where it gets specific and you gotta pay attention, bestie:

• for file pages, this is the offset from the beginning of the file, measured in units of PAGE_SIZE.
• for anonymous pages, this is the offset from the beginning of the anon_vma, also in units of PAGE_SIZE.
• and for KSM pages? yeah no, this will return nonsense. literally nonsense. don't come for me, that's just what the page says 💀

---

🔥 CONTEXT 🔥

the caller must have a reference on the folio, or otherwise prevent it from being split or freed. no cap — that's a hard requirement, not a suggestion. hold your reference, bestie 🙈

---

👑 RETURN 👑

the offset, in units of PAGE_SIZE. simple. clean. slay ⭐

---

🧚 SEE ALSO 🧚

so many friends, all from the kernel file ./include/linux/pagemap.h. go say hi 💜

• filemap_set_wb_err(9)
• filemap_check_wb_err(9)
• filemap_sample_wb_err(9)
• file_sample_sb_err(9)
• mapping_set_error(9)
• mapping_set_large_folios(9)
• mapping_align_index(9)
• mapping_pmd_folio_support(9)
• folio_flush_mapping(9)
• folio_inode(9)
• folio_attach_private(9)
• folio_change_private(9)
• folio_detach_private(9)
• fgf_t(9)
• fgf_set_order(9)
• write_begin_get_folio(9)
• filemap_get_folio(9)
• filemap_lock_folio(9)
• filemap_grab_folio(9)
• find_get_page(9)
• find_lock_page(9)
• find_or_create_page(9)
• grab_cache_page_nowait(9)
• folio_next_index(9)
• folio_next_pos(9)
• folio_file_page(9)
• folio_contains(9)
• folio_pos(9)
• linear_page_delta(9)
• linear_page_index(9)
• linear_anon_page_index(9)
• folio_trylock(9)
• folio_lock(9)
• lock_page(9)
• folio_lock_killable(9)
• filemap_range_needs_writeback(9)
• struct readahead_control(9)
• page_cache_sync_readahead(9)
• page_cache_async_readahead(9)
• readahead_folio(9)
• readahead_pos(9)
• readahead_length(9)
• readahead_index(9)
• readahead_count(9)
• readahead_batch_length(9)
• folio_mkwrite_check_truncate(9)
• i_blocks_per_folio(9)

---

ngl, that's a whole group chat of cross-references and every single one of them made the list. no skips, no cuts 💅

and that's the page!! this one came out of ./include/linux, dated October 2026, and it's still filed under page_pgoff(9) — go off, king 💖✨🎀