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author | Matthew Wilcox (Oracle) <willy@infradead.org> | 2021-08-16 23:36:31 -0400 |
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committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-01-04 13:15:33 -0500 |
commit | 9f2b04a25a41b1f41b3cead4f56854a4192ec5b0 (patch) | |
tree | 27f4d1ed8d4626e3bf9938c1e768eefdc4e4bfd9 /mm | |
parent | 5bf34d7c7ffe773c3b3c1b6ebf39e0f34a2436ec (diff) | |
download | linux-9f2b04a25a41b1f41b3cead4f56854a4192ec5b0.tar.bz2 |
filemap: Add folio_put_wait_locked()
Convert all three callers of put_and_wait_on_page_locked() to
folio_put_wait_locked(). This shrinks the kernel overall by 19 bytes.
filemap_update_page() shrinks by 19 bytes while __migration_entry_wait()
is unchanged. folio_put_wait_locked() is 14 bytes smaller than
put_and_wait_on_page_locked(), but pmd_migration_entry_wait() grows by
14 bytes. It removes the assumption from pmd_migration_entry_wait()
that pages cannot be larger than a PMD (which is true today, but
may be interesting to explore in the future).
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/filemap.c | 27 | ||||
-rw-r--r-- | mm/migrate.c | 21 |
2 files changed, 25 insertions, 23 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 39c4c46c6133..5dd3c6e39c9f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1259,10 +1259,10 @@ enum behavior { * __folio_lock() waiting on then setting PG_locked. */ SHARED, /* Hold ref to page and check the bit when woken, like - * wait_on_page_writeback() waiting on PG_writeback. + * folio_wait_writeback() waiting on PG_writeback. */ DROP, /* Drop ref to page before wait, no check when woken, - * like put_and_wait_on_page_locked() on PG_locked. + * like folio_put_wait_locked() on PG_locked. */ }; @@ -1439,22 +1439,21 @@ int folio_wait_bit_killable(struct folio *folio, int bit_nr) EXPORT_SYMBOL(folio_wait_bit_killable); /** - * put_and_wait_on_page_locked - Drop a reference and wait for it to be unlocked - * @page: The page to wait for. + * folio_put_wait_locked - Drop a reference and wait for it to be unlocked + * @folio: The folio to wait for. * @state: The sleep state (TASK_KILLABLE, TASK_UNINTERRUPTIBLE, etc). * - * The caller should hold a reference on @page. They expect the page to + * The caller should hold a reference on @folio. They expect the page to * become unlocked relatively soon, but do not wish to hold up migration - * (for example) by holding the reference while waiting for the page to + * (for example) by holding the reference while waiting for the folio to * come unlocked. After this function returns, the caller should not - * dereference @page. + * dereference @folio. * - * Return: 0 if the page was unlocked or -EINTR if interrupted by a signal. + * Return: 0 if the folio was unlocked or -EINTR if interrupted by a signal. */ -int put_and_wait_on_page_locked(struct page *page, int state) +int folio_put_wait_locked(struct folio *folio, int state) { - return folio_wait_bit_common(page_folio(page), PG_locked, state, - DROP); + return folio_wait_bit_common(folio, PG_locked, state, DROP); } /** @@ -2447,7 +2446,11 @@ static int filemap_update_page(struct kiocb *iocb, goto unlock_mapping; if (!(iocb->ki_flags & IOCB_WAITQ)) { filemap_invalidate_unlock_shared(mapping); - put_and_wait_on_page_locked(&folio->page, TASK_KILLABLE); + /* + * This is where we usually end up waiting for a + * previously submitted readahead to finish. + */ + folio_put_wait_locked(folio, TASK_KILLABLE); return AOP_TRUNCATED_PAGE; } error = __folio_lock_async(folio, iocb->ki_waitq); diff --git a/mm/migrate.c b/mm/migrate.c index cf25b00f03c8..311638177536 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -291,7 +291,7 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, { pte_t pte; swp_entry_t entry; - struct page *page; + struct folio *folio; spin_lock(ptl); pte = *ptep; @@ -302,18 +302,17 @@ void __migration_entry_wait(struct mm_struct *mm, pte_t *ptep, if (!is_migration_entry(entry)) goto out; - page = pfn_swap_entry_to_page(entry); - page = compound_head(page); + folio = page_folio(pfn_swap_entry_to_page(entry)); /* * Once page cache replacement of page migration started, page_count - * is zero; but we must not call put_and_wait_on_page_locked() without - * a ref. Use get_page_unless_zero(), and just fault again if it fails. + * is zero; but we must not call folio_put_wait_locked() without + * a ref. Use folio_try_get(), and just fault again if it fails. */ - if (!get_page_unless_zero(page)) + if (!folio_try_get(folio)) goto out; pte_unmap_unlock(ptep, ptl); - put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE); + folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE); return; out: pte_unmap_unlock(ptep, ptl); @@ -338,16 +337,16 @@ void migration_entry_wait_huge(struct vm_area_struct *vma, void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd) { spinlock_t *ptl; - struct page *page; + struct folio *folio; ptl = pmd_lock(mm, pmd); if (!is_pmd_migration_entry(*pmd)) goto unlock; - page = pfn_swap_entry_to_page(pmd_to_swp_entry(*pmd)); - if (!get_page_unless_zero(page)) + folio = page_folio(pfn_swap_entry_to_page(pmd_to_swp_entry(*pmd))); + if (!folio_try_get(folio)) goto unlock; spin_unlock(ptl); - put_and_wait_on_page_locked(page, TASK_UNINTERRUPTIBLE); + folio_put_wait_locked(folio, TASK_UNINTERRUPTIBLE); return; unlock: spin_unlock(ptl); |