From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
To: linux-mm@kvack.org
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org
Subject: [PATCH v4 13/25] mm/filemap: Add lock_folio
Date: Fri, 5 Mar 2021 04:18:49 +0000 [thread overview]
Message-ID: <20210305041901.2396498-14-willy@infradead.org> (raw)
In-Reply-To: <20210305041901.2396498-1-willy@infradead.org>
This is like lock_page() but for use by callers who know they have a folio.
Convert __lock_page() to be __lock_folio(). This saves one call to
compound_head() per contended call to lock_page().
Saves 362 bytes of text; mostly from improved register allocation and
inlining decisions. __lock_folio is 59 bytes while __lock_page was 79.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/pagemap.h | 24 +++++++++++++++++++-----
mm/filemap.c | 29 +++++++++++++++--------------
2 files changed, 34 insertions(+), 19 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index a34cf531c100..034e41256340 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -635,7 +635,7 @@ static inline bool wake_page_match(struct wait_page_queue *wait_page,
return true;
}
-extern void __lock_page(struct page *page);
+void __lock_folio(struct folio *folio);
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,
@@ -643,13 +643,24 @@ extern int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
void unlock_page(struct page *page);
void unlock_folio(struct folio *folio);
+static inline bool trylock_folio(struct folio *folio)
+{
+ return likely(!test_and_set_bit_lock(PG_locked, folio_flags(folio)));
+}
+
/*
* Return true if the page was successfully locked
*/
static inline int trylock_page(struct page *page)
{
- page = compound_head(page);
- return (likely(!test_and_set_bit_lock(PG_locked, &page->flags)));
+ return trylock_folio(page_folio(page));
+}
+
+static inline void lock_folio(struct folio *folio)
+{
+ might_sleep();
+ if (!trylock_folio(folio))
+ __lock_folio(folio);
}
/*
@@ -657,9 +668,12 @@ static inline int trylock_page(struct page *page)
*/
static inline void lock_page(struct page *page)
{
+ struct folio *folio;
might_sleep();
- if (!trylock_page(page))
- __lock_page(page);
+
+ folio = page_folio(page);
+ if (!trylock_folio(folio))
+ __lock_folio(folio);
}
/*
diff --git a/mm/filemap.c b/mm/filemap.c
index 9960ef1b2758..3e3e3c666b94 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1160,7 +1160,7 @@ static void wake_up_page(struct page *page, int bit)
*/
enum behavior {
EXCLUSIVE, /* Hold ref to page and take the bit when woken, like
- * __lock_page() waiting on then setting PG_locked.
+ * __lock_folio() 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.
@@ -1488,17 +1488,16 @@ void page_endio(struct page *page, bool is_write, int err)
EXPORT_SYMBOL_GPL(page_endio);
/**
- * __lock_page - get a lock on the page, assuming we need to sleep to get it
- * @__page: the page to lock
+ * __lock_folio - Get a lock on the folio, assuming we need to sleep to get it.
+ * @folio: The folio to lock
*/
-void __lock_page(struct page *__page)
+void __lock_folio(struct folio *folio)
{
- struct page *page = compound_head(__page);
- wait_queue_head_t *q = page_waitqueue(page);
- wait_on_page_bit_common(q, page, PG_locked, TASK_UNINTERRUPTIBLE,
+ wait_queue_head_t *q = page_waitqueue(&folio->page);
+ wait_on_page_bit_common(q, &folio->page, PG_locked, TASK_UNINTERRUPTIBLE,
EXCLUSIVE);
}
-EXPORT_SYMBOL(__lock_page);
+EXPORT_SYMBOL(__lock_folio);
int __lock_page_killable(struct page *__page)
{
@@ -1573,10 +1572,10 @@ int __lock_page_or_retry(struct page *page, struct mm_struct *mm,
return 0;
}
} else {
- __lock_page(page);
+ __lock_folio(page_folio(page));
}
- return 1;
+ return 1;
}
/**
@@ -2720,7 +2719,9 @@ loff_t mapping_seek_hole_data(struct address_space *mapping, loff_t start,
static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
struct file **fpin)
{
- if (trylock_page(page))
+ struct folio *folio = page_folio(page);
+
+ if (trylock_folio(folio))
return 1;
/*
@@ -2733,7 +2734,7 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
*fpin = maybe_unlock_mmap_for_io(vmf, *fpin);
if (vmf->flags & FAULT_FLAG_KILLABLE) {
- if (__lock_page_killable(page)) {
+ if (__lock_page_killable(&folio->page)) {
/*
* We didn't have the right flags to drop the mmap_lock,
* but all fault_handlers only check for fatal signals
@@ -2745,11 +2746,11 @@ static int lock_page_maybe_drop_mmap(struct vm_fault *vmf, struct page *page,
return 0;
}
} else
- __lock_page(page);
+ __lock_folio(folio);
+
return 1;
}
-
/*
* Synchronous readahead happens when we don't even find a page in the page
* cache at all. We don't want to perform IO under the mmap sem, so if we have
--
2.30.0
next prev parent reply other threads:[~2021-03-05 4:23 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-05 4:18 [PATCH v4 00/25] Page folios Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 01/25] mm: Introduce struct folio Matthew Wilcox (Oracle)
2021-03-13 20:37 ` Andrew Morton
2021-03-14 4:07 ` Matthew Wilcox
2021-03-17 17:14 ` Christoph Hellwig
2021-03-18 23:56 ` Balbir Singh
2021-03-19 1:25 ` Matthew Wilcox
2021-03-20 2:09 ` Balbir Singh
2021-03-22 2:52 ` Nicholas Piggin
2021-03-22 3:54 ` Matthew Wilcox
2021-03-05 4:18 ` [PATCH v4 02/25] mm: Add folio_pgdat and folio_zone Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 03/25] mm/vmstat: Add functions to account folio statistics Matthew Wilcox (Oracle)
2021-03-13 20:37 ` Andrew Morton
2021-03-14 4:11 ` Matthew Wilcox
2021-03-14 4:51 ` Andrew Morton
2021-03-17 17:16 ` Christoph Hellwig
2021-03-05 4:18 ` [PATCH v4 04/25] mm/debug: Add VM_BUG_ON_FOLIO and VM_WARN_ON_ONCE_FOLIO Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 05/25] mm: Add put_folio Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 06/25] mm: Add get_folio Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 07/25] mm: Create FolioFlags Matthew Wilcox (Oracle)
2021-03-15 2:24 ` Matthew Wilcox
2021-03-05 4:18 ` [PATCH v4 08/25] mm: Handle per-folio private data Matthew Wilcox (Oracle)
2021-03-17 17:20 ` Christoph Hellwig
2021-03-18 17:57 ` Matthew Wilcox
2021-03-05 4:18 ` [PATCH v4 09/25] mm: Add folio_index, folio_page and folio_contains Matthew Wilcox (Oracle)
2021-03-13 20:37 ` Andrew Morton
2021-03-14 3:45 ` Matthew Wilcox
2021-03-17 17:22 ` Christoph Hellwig
2021-03-05 4:18 ` [PATCH v4 10/25] mm/util: Add folio_mapping and folio_file_mapping Matthew Wilcox (Oracle)
2021-03-17 17:26 ` Christoph Hellwig
2021-03-05 4:18 ` [PATCH v4 11/25] mm/memcg: Add folio wrappers for various memcontrol functions Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 12/25] mm/filemap: Add unlock_folio Matthew Wilcox (Oracle)
2021-03-05 4:18 ` Matthew Wilcox (Oracle) [this message]
2021-03-05 4:18 ` [PATCH v4 14/25] mm/filemap: Add lock_folio_killable Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 15/25] mm/filemap: Convert lock_page_async to lock_folio_async Matthew Wilcox (Oracle)
2021-03-17 17:29 ` Christoph Hellwig
2021-03-05 4:18 ` [PATCH v4 16/25] mm/filemap: Convert end_page_writeback to end_folio_writeback Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 17/25] mm/filemap: Add wait_on_folio_locked & wait_on_folio_locked_killable Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 18/25] mm/page-writeback: Add wait_on_folio_writeback Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 19/25] mm/page-writeback: Add wait_for_stable_folio Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 20/25] mm/filemap: Convert wait_on_page_bit to wait_on_folio_bit Matthew Wilcox (Oracle)
2021-03-17 17:39 ` Christoph Hellwig
2021-03-05 4:18 ` [PATCH v4 21/25] mm/filemap: Add __lock_folio_or_retry Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 22/25] mm/filemap: Convert wake_up_page_bit to wake_up_folio_bit Matthew Wilcox (Oracle)
2021-03-05 4:18 ` [PATCH v4 23/25] mm/page-writeback: Convert test_clear_page_writeback to take a folio Matthew Wilcox (Oracle)
2021-03-05 4:19 ` [PATCH v4 24/25] mm/filemap: Convert page wait queues to be folios Matthew Wilcox (Oracle)
2021-03-05 4:19 ` [PATCH v4 25/25] cachefiles: Switch to wait_page_key Matthew Wilcox (Oracle)
2021-03-17 17:45 ` Christoph Hellwig
2021-03-13 20:36 ` [PATCH v4 00/25] Page folios Andrew Morton
2021-03-14 2:30 ` Matthew Wilcox
2021-03-14 3:09 ` Hugh Dickins
[not found] ` <20210315115501.7rmzaan2hxsqowgq@box>
2021-03-15 13:45 ` Matthew Wilcox
[not found] ` <YE9VLGl50hLIJHci@dhcp22.suse.cz>
2021-03-15 19:09 ` Christoph Hellwig
2021-03-15 19:40 ` Matthew Wilcox
2021-03-15 22:27 ` Dave Chinner
2021-03-17 17:48 ` Christoph Hellwig
2021-03-15 21:33 ` Andi Kleen
2021-03-19 4:01 ` Matthew Wilcox
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