From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-fsdevel@vger.kernel.org, linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org
Subject: [PATCH 05/25] mm: Add unlock_folio
Date: Wed, 16 Dec 2020 18:23:15 +0000 [thread overview]
Message-ID: <20201216182335.27227-6-willy@infradead.org> (raw)
In-Reply-To: <20201216182335.27227-1-willy@infradead.org>
Convert unlock_page() to call unlock_folio(). By using a folio we avoid
doing a repeated compound_head() This shortens the function from 120
bytes to 76 bytes.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/pagemap.h | 16 +++++++++++++++-
mm/filemap.c | 27 ++++++++++-----------------
2 files changed, 25 insertions(+), 18 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index b5af2c3719ab..83786e7eeb23 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -604,7 +604,21 @@ extern int __lock_page_killable(struct page *page);
extern int __lock_page_async(struct page *page, struct wait_page_queue *wait);
extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
unsigned int flags);
-extern void unlock_page(struct page *page);
+extern void unlock_folio(struct folio *folio);
+
+/**
+ * unlock_page - Unlock a locked page.
+ * @page: The page.
+ *
+ * Unlocks the page and wakes up any thread sleeping on the page lock.
+ *
+ * Context: May be called from interrupt or process context. May not be
+ * called from NMI context.
+ */
+static inline void unlock_page(struct page *page)
+{
+ return unlock_folio(page_folio(page));
+}
/*
* Return true if the page was successfully locked
diff --git a/mm/filemap.c b/mm/filemap.c
index 13ef23f72330..8af89ecc1452 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1443,29 +1443,22 @@ static inline bool clear_bit_unlock_is_negative_byte(long nr, volatile void *mem
#endif
/**
- * unlock_page - unlock a locked page
- * @page: the page
+ * unlock_folio - Unlock a locked folio.
+ * @folio: The folio.
*
- * Unlocks the page and wakes up sleepers in wait_on_page_locked().
- * Also wakes sleepers in wait_on_page_writeback() because the wakeup
- * mechanism between PageLocked pages and PageWriteback pages is shared.
- * But that's OK - sleepers in wait_on_page_writeback() just go back to sleep.
+ * Unlocks the folio and wakes up any thread sleeping on the page lock.
*
- * Note that this depends on PG_waiters being the sign bit in the byte
- * that contains PG_locked - thus the BUILD_BUG_ON(). That allows us to
- * clear the PG_locked bit and test PG_waiters at the same time fairly
- * portably (architectures that do LL/SC can test any bit, while x86 can
- * test the sign bit).
+ * Context: May be called from interrupt or process context. May not be
+ * called from NMI context.
*/
-void unlock_page(struct page *page)
+void unlock_folio(struct folio *folio)
{
BUILD_BUG_ON(PG_waiters != 7);
- page = compound_head(page);
- VM_BUG_ON_PAGE(!PageLocked(page), page);
- if (clear_bit_unlock_is_negative_byte(PG_locked, &page->flags))
- wake_up_page_bit(page, PG_locked);
+ VM_BUG_ON_PAGE(!FolioLocked(folio), &folio->page);
+ if (clear_bit_unlock_is_negative_byte(PG_locked, folio_flags(folio)))
+ wake_up_page_bit(&folio->page, PG_locked);
}
-EXPORT_SYMBOL(unlock_page);
+EXPORT_SYMBOL(unlock_folio);
/**
* end_page_writeback - end writeback against a page
--
2.29.2
next prev parent reply other threads:[~2020-12-16 18:23 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-16 18:23 [PATCH 00/25] Page folios Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 01/25] mm: Introduce struct folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 02/25] mm: Add put_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 03/25] mm: Add get_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 04/25] mm: Create FolioFlags Matthew Wilcox (Oracle)
2020-12-16 18:23 ` Matthew Wilcox (Oracle) [this message]
2020-12-16 18:23 ` [PATCH 06/25] mm: Add lock_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 07/25] mm: Add lock_folio_killable Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 08/25] mm: Add __alloc_folio_node and alloc_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 09/25] mm: Convert __page_cache_alloc to return a folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 10/25] mm/filemap: Convert end_page_writeback to use " Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 11/25] mm: Convert mapping_get_entry to return " Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 12/25] mm: Add mark_folio_accessed Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 13/25] mm: Add filemap_get_folio and find_get_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 14/25] mm/filemap: Add folio_add_to_page_cache Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 15/25] mm/swap: Convert rotate_reclaimable_page to folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 16/25] mm: Add folio_mapping Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 17/25] mm: Rename THP_SUPPORT to MULTI_PAGE_FOLIOS Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 18/25] btrfs: Use readahead_batch_length Matthew Wilcox (Oracle)
2020-12-17 9:15 ` John Hubbard
2020-12-17 12:12 ` Matthew Wilcox
2020-12-17 13:42 ` Matthew Wilcox
2020-12-17 19:36 ` John Hubbard
2020-12-16 18:23 ` [PATCH 19/25] fs: Change page refcount rules for readahead Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 20/25] fs: Change readpage to take a folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 21/25] mm: Convert wait_on_page_bit to wait_on_folio_bit Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 22/25] mm: Add wait_on_folio_locked & wait_on_folio_locked_killable Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 23/25] mm: Add flush_dcache_folio Matthew Wilcox (Oracle)
2020-12-16 20:59 ` kernel test robot
2020-12-16 22:01 ` Matthew Wilcox
2020-12-16 18:23 ` [PATCH 24/25] mm: Add read_cache_folio and read_mapping_folio Matthew Wilcox (Oracle)
2020-12-16 18:23 ` [PATCH 25/25] fs: Convert vfs_dedupe_file_range_compare to folios Matthew Wilcox (Oracle)
2020-12-17 12:47 ` [PATCH 00/25] Page folios David Hildenbrand
2020-12-17 13:55 ` Matthew Wilcox
2020-12-17 14:35 ` David Hildenbrand
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